Identification of genetic elements in metabolism by high-throughput mouse phenotyping.

PubMed

Rozman, Jan; Rathkolb, Birgit; Oestereicher, Manuela A; Schütt, Christine; Ravindranath, Aakash Chavan; Leuchtenberger, Stefanie; Sharma, Sapna; Kistler, Martin; Willershäuser, Monja; Brommage, Robert; Meehan, Terrence F; Mason, Jeremy; Haselimashhadi, Hamed; Hough, Tertius; Mallon, Ann-Marie; Wells, Sara; Santos, Luis; Lelliott, Christopher J; White, Jacqueline K; Sorg, Tania; Champy, Marie-France; Bower, Lynette R; Reynolds, Corey L; Flenniken, Ann M; Murray, Stephen A; Nutter, Lauryl M J; Svenson, Karen L; West, David; Tocchini-Valentini, Glauco P; Beaudet, Arthur L; Bosch, Fatima; Braun, Robert B; Dobbie, Michael S; Gao, Xiang; Herault, Yann; Moshiri, Ala; Moore, Bret A; Kent Lloyd, K C; McKerlie, Colin; Masuya, Hiroshi; Tanaka, Nobuhiko; Flicek, Paul; Parkinson, Helen E; Sedlacek, Radislav; Seong, Je Kyung; Wang, Chi-Kuang Leo; Moore, Mark; Brown, Steve D; Tschöp, Matthias H; Wurst, Wolfgang; Klingenspor, Martin; Wolf, Eckhard; Beckers, Johannes; Machicao, Fausto; Peter, Andreas; Staiger, Harald; Häring, Hans-Ulrich; Grallert, Harald; Campillos, Monica; Maier, Holger; Fuchs, Helmut; Gailus-Durner, Valerie; Werner, Thomas; Hrabe de Angelis, Martin

2018-01-18

Metabolic diseases are a worldwide problem but the underlying genetic factors and their relevance to metabolic disease remain incompletely understood. Genome-wide research is needed to characterize so-far unannotated mammalian metabolic genes. Here, we generate and analyze metabolic phenotypic data of 2016 knockout mouse strains under the aegis of the International Mouse Phenotyping Consortium (IMPC) and find 974 gene knockouts with strong metabolic phenotypes. 429 of those had no previous link to metabolism and 51 genes remain functionally completely unannotated. We compared human orthologues of these uncharacterized genes in five GWAS consortia and indeed 23 candidate genes are associated with metabolic disease. We further identify common regulatory elements in promoters of candidate genes. As each regulatory element is composed of several transcription factor binding sites, our data reveal an extensive metabolic phenotype-associated network of co-regulated genes. Our systematic mouse phenotype analysis thus paves the way for full functional annotation of the genome.

T2N as a new tool for robust electrophysiological modeling demonstrated for mature and adult-born dentate granule cells

PubMed Central

Mongiat, Lucas Alberto; Schwarzacher, Stephan Wolfgang

2017-01-01

Compartmental models are the theoretical tool of choice for understanding single neuron computations. However, many models are incomplete, built ad hoc and require tuning for each novel condition rendering them of limited usability. Here, we present T2N, a powerful interface to control NEURON with Matlab and TREES toolbox, which supports generating models stable over a broad range of reconstructed and synthetic morphologies. We illustrate this for a novel, highly detailed active model of dentate granule cells (GCs) replicating a wide palette of experiments from various labs. By implementing known differences in ion channel composition and morphology, our model reproduces data from mouse or rat, mature or adult-born GCs as well as pharmacological interventions and epileptic conditions. This work sets a new benchmark for detailed compartmental modeling. T2N is suitable for creating robust models useful for large-scale networks that could lead to novel predictions. We discuss possible T2N application in degeneracy studies. PMID:29165247

Genomic Organization of the Murine Miller–Dieker/Lissencephaly Region: Conservation of Linkage with the Human Region

PubMed Central

Hirotsune, Shinji; Pack, Svetlana D.; Chong, Samuel S.; Robbins, Christiane M.; Pavan, William J.; Ledbetter, David H.; Wynshaw-Boris, Anthony

1997-01-01

Several human syndromes are associated with haploinsufficiency of chromosomal regions secondary to microdeletions. Isolated lissencephaly sequence (ILS), a human developmental disease characterized by a smooth cerebral surface (classical lissencephaly) and microscopic evidence of incomplete neuronal migration, is often associated with small deletions or translocations at chromosome 17p13.3. Miller–Dieker syndrome (MDS) is associated with larger deletions of 17p13.3 and consists of classical lissencephaly with additional phenotypes including facial abnormalities. We have isolated the murine homologs of three genes located inside and outside the MDS region: Lis1, Mnt/Rox, and 14-3-3ε. These genes are all located on mouse chromosome 11B2, as determined by metaphase FISH, and the relative order and approximate gene distance was determined by interphase FISH analysis. The transcriptional orientation and intergenic distance of Lis1 and Mnt/Rox were ascertained by fragmentation analysis of a mouse yeast artificial chromosome containing both genes. To determine the distance and orientation of 14-3-3ε with respect to Lis1 and Mnt/Rox, we introduced a super-rare cutter site (VDE) that is unique in the mouse genome into 14-3-3ε by gene targeting. Using the introduced VDE site, the orientation of this gene was determined by pulsed field gel electrophoresis and Southern blot analysis. Our results demonstrate that the MDS region is conserved between human and mouse. This conservation of linkage suggests that the mouse can be used to model microdeletions that occur in ILS and MDS. PMID:9199935

Murine immunization with CS21 pili or LngA major subunit of enterotoxigenic Escherichia coli (ETEC) elicits systemic and mucosal immune responses and inhibits ETEC gut colonization.

PubMed

Zhang, Chengxian; Iqbal, Junaid; Gómez-Duarte, Oscar G

2017-04-01

CS21 pili of enterotoxigenic Escherichia coli (ETEC) is one of the most prevalent ETEC colonization factors. CS21 major subunit, LngA, mediates ETEC adherence to intestinal cells, and contributes to ETEC pathogenesis in a neonatal mouse infection model. The objectives of this work were to evaluate LngA major subunit purified protein and CS21 purified pili on immunogenicity and protection against ETEC colonization of mice intestine. Recombinant LngA purified protein or purified CS21 pili from E9034A ETEC strain were evaluated for immunogenicity after immunization of C57BL/6 mice. Specific anti-LngA antibodies were detected from mice serum, feces, and intestine fluid samples by ELISA assays. Protection against gut colonization was evaluated on immunized mice orally challenged with wild type E9034A ETEC strain and by subsequent quantification of bacterial colony forming units (CFU) recovered from feces. Recombinant LngA protein and CS21 pili induced specific humoral and mucosal anti-LngA antibodies in the mouse model. CS21 combined with CT delivered intranasally as well as LngA combined with incomplete Freund adjuvant delivered intraperitoneally inhibited ETEC gut colonization in a mouse model. In conclusion, both LngA purified protein and CS21 pili from ETEC are highly immunogenic and may inhibit ETEC intestinal shedding. Our data on immunogenicity and immunoprotection indicates that CS21 is a suitable vaccine candidate for a future multivalent vaccine against ETEC diarrhea. Copyright © 2016 Elsevier B.V. All rights reserved.

An operant-based detection method for inferring tinnitus in mice.

PubMed

Zuo, Hongyan; Lei, Debin; Sivaramakrishnan, Shobhana; Howie, Benjamin; Mulvany, Jessica; Bao, Jianxin

2017-11-01

Subjective tinnitus is a hearing disorder in which a person perceives sound when no external sound is present. It can be acute or chronic. Because our current understanding of its pathology is incomplete, no effective cures have yet been established. Mouse models are useful for studying the pathophysiology of tinnitus as well as for developing therapeutic treatments. We have developed a new method for determining acute and chronic tinnitus in mice, called sound-based avoidance detection (SBAD). The SBAD method utilizes one paradigm to detect tinnitus and another paradigm to monitor possible confounding factors, such as motor impairment, loss of motivation, and deficits in learning and memory. The SBAD method has succeeded in monitoring both acute and chronic tinnitus in mice. Its detection ability is further validated by functional studies demonstrating an abnormal increase in neuronal activity in the inferior colliculus of mice that had previously been identified as having tinnitus by the SBAD method. The SBAD method provides a new means by which investigators can detect tinnitus in a single mouse accurately and with more control over potential confounding factors than existing methods. This work establishes a new behavioral method for detecting tinnitus in mice. The detection outcome is consistent with functional validation. One key advantage of mouse models is they provide researchers the opportunity to utilize an extensive array of genetic tools. This new method could lead to a deeper understanding of the molecular pathways underlying tinnitus pathology. Copyright © 2017 Elsevier B.V. All rights reserved.

Schwann cells use TAM receptor-mediated phagocytosis in addition to autophagy to clear myelin in a mouse model of nerve injury.

PubMed

Brosius Lutz, Amanda; Chung, Won-Suk; Sloan, Steven A; Carson, Glenn A; Zhou, Lu; Lovelett, Emilie; Posada, Sean; Zuchero, J Bradley; Barres, Ben A

2017-09-19

Ineffective myelin debris clearance is a major factor contributing to the poor regenerative ability of the central nervous system. In stark contrast, rapid clearance of myelin debris from the injured peripheral nervous system (PNS) is one of the keys to this system's remarkable regenerative capacity, but the molecular mechanisms driving PNS myelin clearance are incompletely understood. We set out to discover new pathways of PNS myelin clearance to identify novel strategies for activating myelin clearance in the injured central nervous system, where myelin debris is not cleared efficiently. Here we show that Schwann cells, the myelinating glia of the PNS, collaborate with hematogenous macrophages to clear myelin debris using TAM (Tyro3, Axl, Mer) receptor-mediated phagocytosis as well as autophagy. In a mouse model of PNS nerve crush injury, Schwann cells up-regulate TAM phagocytic receptors Axl and Mertk following PNS injury, and Schwann cells lacking both of these phagocytic receptors exhibit significantly impaired myelin phagocytosis both in vitro and in vivo. Autophagy-deficient Schwann cells also display reductions in myelin clearance after mouse nerve crush injury, as has been recently shown following nerve transection. These findings add a mechanism, Axl/Mertk-mediated myelin clearance, to the repertoire of cellular machinery used to clear myelin in the injured PNS. Given recent evidence that astrocytes express Axl and Mertk and have previously unrecognized phagocytic potential, this pathway may be a promising avenue for activating myelin clearance after CNS injury.

The structure of mouse cytomegalovirus m04 protein obtained from sparse NMR data reveals a conserved fold of the m02-m06 viral immune modulator family.

PubMed

Sgourakis, Nikolaos G; Natarajan, Kannan; Ying, Jinfa; Vogeli, Beat; Boyd, Lisa F; Margulies, David H; Bax, Ad

2014-09-02

Immunoevasins are key proteins used by viruses to subvert host immune responses. Determining their high-resolution structures is key to understanding virus-host interactions toward the design of vaccines and other antiviral therapies. Mouse cytomegalovirus encodes a unique set of immunoevasins, the m02-m06 family, that modulates major histocompatibility complex class I (MHC-I) antigen presentation to CD8+ T cells and natural killer cells. Notwithstanding the large number of genetic and functional studies, the structural biology of immunoevasins remains incompletely understood, largely because of crystallization bottlenecks. Here we implement a technology using sparse nuclear magnetic resonance data and integrative Rosetta modeling to determine the structure of the m04/gp34 immunoevasin extracellular domain. The structure reveals a β fold that is representative of the m02-m06 family of viral proteins, several of which are known to bind MHC-I molecules and interfere with antigen presentation, suggesting its role as a diversified immune regulation module. Copyright © 2014 Elsevier Ltd. All rights reserved.

Inhibition of TRPC3 downregulates airway hyperresponsiveness, remodeling of OVA-sensitized mouse.

PubMed

Wang, Lingwei; Li, Jie; Zhang, Jian; He, Qi; Weng, Xuanwen; Huang, Yanmei; Guan, Minjie; Qiu, Chen

2017-02-26

Airway hyperresponsiveness (AHR), airway remodeling and inflammation are the fundamental pathological alterations that occur in asthma. Transient receptor potential canonical 3 (TRPC3) has been implicated in diverse functions of airway smooth muscle cells (ASMCs) in asthma. However, the underlying mechanisms remain incompletely understood. We investigated the mRNA and protein expression of TRPC3 in ASMCs from normal and OVA-sensitized mouse. And the effects of inhibition or knockdown of TRPC3 with Ethyl-1- (4- (2,3,3-trichloroacrylamide) phenyl) -5 - (trifluoromethyl) -1H -pyrazole -4-carboxylate (Pyr3) and lentiviral shRNA on OVA-sensitized mouse AHR, airway remodeling, circulating inflammatory cytokines, cell proliferation and migration. We found that TRPC3 mRNA and protein expression levels were significantly increased in ASMCs from OVA-sensitized mouse. Inhibiting TRPC3 with continuous subcutaneous administration of Pyr3 decreased enhanced pause (Penh) of OVA-sensitized mouse. Meanwhile, both Pyr3 and lentiviral shRNA treatment of ASMCs in OVA-sensitized mouse significantly decreased their proliferation and migration. These results suggest that TRPC3 plays a critical role in asthma and represents a promising new target for asthma treatment. Copyright © 2016 Elsevier Inc. All rights reserved.

Biological effects of CCS in the absence of SOD1 enzyme activation: implications for disease in a mouse model for ALS.

PubMed

Proescher, Jody B; Son, Marjatta; Elliott, Jeffrey L; Culotta, Valeria C

2008-06-15

The CCS copper chaperone is critical for maturation of Cu, Zn-superoxide dismutase (SOD1) through insertion of the copper co-factor and oxidization of an intra-subunit disulfide. The disulfide helps stabilize the SOD1 polypeptide, which can be particularly important in cases of amyotrophic lateral sclerosis (ALS) linked to misfolding of mutant SOD1. Surprisingly, however, over-expressed CCS was recently shown to greatly accelerate disease in a G93A SOD1 mouse model for ALS. Herein we show that disease in these G93A/CCS mice correlates with incomplete oxidation of the SOD1 disulfide. In the brain and spinal cord, CCS over-expression failed to enhance oxidation of the G93A SOD1 disulfide and if anything, effected some accumulation of disulfide-reduced SOD1. This effect was mirrored in culture with a C244,246S mutant of CCS that has the capacity to interact with SOD1 but can neither insert copper nor oxidize the disulfide. In spite of disulfide effects, there was no evidence for increased SOD1 aggregation. If anything, CCS over-expression prevented SOD1 misfolding in culture as monitored by detergent insolubility. This protection against SOD1 misfolding does not require SOD1 enzyme activation as the same effect was obtained with the C244,246S allele of CCS. In the G93A SOD1 mouse, CCS over-expression was likewise associated with a lack of obvious SOD1 misfolding marked by detergent insolubility. CCS over-expression accelerates SOD1-linked disease without the hallmarks of misfolding and aggregation seen in other mutant SOD1 models. These studies are the first to indicate biological effects of CCS in the absence of SOD1 enzymatic activation.

Peroxisome proliferator-activated receptor δ promotes the progression of posttraumatic osteoarthritis in a mouse model.

PubMed

Ratneswaran, A; LeBlanc, E A; Walser, E; Welch, I; Mort, J S; Borradaile, N; Beier, F

2015-02-01

Osteoarthritis (OA) is a serious disease of the entire joint, characterized by articular cartilage degeneration, subchondral bone changes, osteophyte formation, and synovial hyperplasia. Currently, there are no pharmaceutical treatments that can slow the disease progression, resulting in greatly reduced quality of life for patients and the need for joint replacement surgeries in many cases. The lack of available treatments for OA is partly due to our incomplete understanding of the molecular mechanisms that promote disease initiation and progression. The purpose of the present study was to examine the role of the nuclear receptor peroxisome proliferator-activated receptor δ (PPARδ) as a promoter of cartilage degeneration in a mouse model of posttraumatic OA. Mouse chondrocytes and knee explants were treated with a pharmacologic agonist of PPARδ (GW501516) to evaluate changes in gene expression, histologic features, and matrix glycosaminoglycan breakdown. In vivo, PPARδ was specifically deleted from the cartilage of mice. Histopathologic scoring according to the Osteoarthritis Research Society International (OARSI) system and immunohistochemical analysis were used to compare mutant and control mice subjected to surgical destabilization of the medial meniscus (DMM). In vitro, PPARδ activation by GW501516 resulted in increased expression of several proteases in chondrocytes, as well as aggrecan degradation and glycosaminoglycan release in knee joint explants. In vivo, cartilage-specific PPARδ-knockout mice did not display any abnormalities of skeletal development but showed marked protection in the DMM model of posttraumatic OA (as compared to control littermates). OARSI scoring and immunohistochemical analyses confirmed strong protection of mutant mice from DMM-induced cartilage degeneration. These data demonstrate a catabolic role of endogenous PPARδ in posttraumatic OA and suggest that pharmacologic inhibition of PPARδ is a promising therapeutic strategy. Copyright © 2015 by the American College of Rheumatology.

Study of smell and reproductive organs in a mouse model for CHARGE syndrome

PubMed Central

Bergman, Jorieke EH; Bosman, Erika A; van Ravenswaaij-Arts, Conny MA; Steel, Karen P

2010-01-01

CHARGE syndrome is a multiple congenital anomaly syndrome characterised by Coloboma, Heart defects, Atresia of choanae, Retardation of growth and/or development, Genital hypoplasia, and Ear anomalies often associated with deafness. It is caused by heterozygous mutations in the CHD7 gene and shows a highly variable phenotype. Anosmia and hypogonadotropic hypogonadism occur in the majority of the CHARGE patients, but the underlying pathogenesis is unknown. Therefore, we studied the ability to smell and aspects of the reproductive system (reproductive performance, gonadotropin-releasing hormone (GnRH) neurons and anatomy of testes and uteri) in a mouse model for CHARGE syndrome, the whirligig mouse (Chd7Whi/+). We showed that Chromodomain Helicase DNA-binding protein 7 (Chd7) is expressed in brain areas involved in olfaction and reproduction during embryonic development. We observed poorer performance in the smell test in adult Chd7Whi/+ mice, secondary either to olfactory dysfunction or to balance disturbances. Olfactory bulb and reproductive organ abnormalities were observed in a proportion of Chd7Whi/+ mice. Hypothalamic GnRH neurons were slightly reduced in Chd7Whi/+ females and reproductive performance was slightly less in Chd7Whi/+ mice. This study shows that the penetrance of anosmia and hypogonadotropic hypogonadism is lower in Chd7Whi/+ mice than in CHARGE patients. Interestingly, many phenotypic features of the Chd7 mutation showed incomplete penetrance in our model mice, despite the use of inbred, genetically identical mice. This supports the theory that the extreme variability of the CHARGE phenotype in both humans and mice might be attributed to variations in the fetal microenvironment or to purely stochastic events. PMID:19809474

Paradoxical leanness in the imprinting-centre deletion mouse model for Prader–Willi syndrome

PubMed Central

Golding, David M; Rees, Daniel J; Davies, Jennifer R; Relkovic, Dinko; Furby, Hannah V; Guschina, Irina A; Hopkins, Anna L; Davies, Jeffrey S; Resnick, James L; Isles, Anthony R

2016-01-01

Prader–Willi syndrome (PWS), a neurodevelopmental disorder caused by loss of paternal gene expression from 15q11–q13, is characterised by growth retardation, hyperphagia and obesity. However, as single gene mutation mouse models for this condition display an incomplete spectrum of the PWS phenotype, we have characterised the metabolic impairment in a mouse model for ‘full’ PWS, in which deletion of the imprinting centre (IC) abolishes paternal gene expression from the entire PWS cluster. We show that PWS-ICdel mice displayed postnatal growth retardation, with reduced body weight, hyperghrelinaemia and marked abdominal leanness; proportionate retroperitoneal, epididymal/omental and inguinal white adipose tissue (WAT) weights being reduced by 82%, 84% and 67%, respectively. PWS-ICdel mice also displayed a 48% reduction in proportionate interscapular brown adipose tissue (isBAT) weight with significant ‘beiging’ of abdominal WAT, and a 2°C increase in interscapular surface body temperature. Maintenance of PWS-ICdel mice under thermoneutral conditions (30°C) suppressed the thermogenic activity in PWS-ICdel males, but failed to elevate the abdominal WAT weight, possibly due to a normalisation of caloric intake. Interestingly, PWS-ICdel mice also showed exaggerated food hoarding behaviour with standard and high-fat diets, but despite becoming hyperphagic when switched to a high-fat diet, PWS-ICdel mice failed to gain weight. This evidence indicates that, unlike humans with PWS, loss of paternal gene expression from the PWS cluster in mice results in abdominal leanness. Although reduced subcutaneous insulation may lead to exaggerated heat loss and thermogenesis, abdominal leanness is likely to arise from a reduced lipid storage capacity rather than increased energy utilisation in BAT. PMID:27799465

Paradoxical leanness in the imprinting-centre deletion mouse model for Prader-Willi syndrome.

PubMed

Golding, David M; Rees, Daniel J; Davies, Jennifer R; Relkovic, Dinko; Furby, Hannah V; Guschina, Irina A; Hopkins, Anna L; Davies, Jeffrey S; Resnick, James L; Isles, Anthony R; Wells, Timothy

2017-01-01

Prader-Willi syndrome (PWS), a neurodevelopmental disorder caused by loss of paternal gene expression from 15q11-q13, is characterised by growth retardation, hyperphagia and obesity. However, as single gene mutation mouse models for this condition display an incomplete spectrum of the PWS phenotype, we have characterised the metabolic impairment in a mouse model for 'full' PWS, in which deletion of the imprinting centre (IC) abolishes paternal gene expression from the entire PWS cluster. We show that PWS-IC del mice displayed postnatal growth retardation, with reduced body weight, hyperghrelinaemia and marked abdominal leanness; proportionate retroperitoneal, epididymal/omental and inguinal white adipose tissue (WAT) weights being reduced by 82%, 84% and 67%, respectively. PWS-IC del mice also displayed a 48% reduction in proportionate interscapular brown adipose tissue (isBAT) weight with significant 'beiging' of abdominal WAT, and a 2°C increase in interscapular surface body temperature. Maintenance of PWS-IC del mice under thermoneutral conditions (30°C) suppressed the thermogenic activity in PWS-IC del males, but failed to elevate the abdominal WAT weight, possibly due to a normalisation of caloric intake. Interestingly, PWS-IC del mice also showed exaggerated food hoarding behaviour with standard and high-fat diets, but despite becoming hyperphagic when switched to a high-fat diet, PWS-IC del mice failed to gain weight. This evidence indicates that, unlike humans with PWS, loss of paternal gene expression from the PWS cluster in mice results in abdominal leanness. Although reduced subcutaneous insulation may lead to exaggerated heat loss and thermogenesis, abdominal leanness is likely to arise from a reduced lipid storage capacity rather than increased energy utilisation in BAT. © 2017 The authors.

High-throughput annotation of full-length long noncoding RNAs with capture long-read sequencing.

PubMed

Lagarde, Julien; Uszczynska-Ratajczak, Barbara; Carbonell, Silvia; Pérez-Lluch, Sílvia; Abad, Amaya; Davis, Carrie; Gingeras, Thomas R; Frankish, Adam; Harrow, Jennifer; Guigo, Roderic; Johnson, Rory

2017-12-01

Accurate annotation of genes and their transcripts is a foundation of genomics, but currently no annotation technique combines throughput and accuracy. As a result, reference gene collections remain incomplete-many gene models are fragmentary, and thousands more remain uncataloged, particularly for long noncoding RNAs (lncRNAs). To accelerate lncRNA annotation, the GENCODE consortium has developed RNA Capture Long Seq (CLS), which combines targeted RNA capture with third-generation long-read sequencing. Here we present an experimental reannotation of the GENCODE intergenic lncRNA populations in matched human and mouse tissues that resulted in novel transcript models for 3,574 and 561 gene loci, respectively. CLS approximately doubled the annotated complexity of targeted loci, outperforming existing short-read techniques. Full-length transcript models produced by CLS enabled us to definitively characterize the genomic features of lncRNAs, including promoter and gene structure, and protein-coding potential. Thus, CLS removes a long-standing bottleneck in transcriptome annotation and generates manual-quality full-length transcript models at high-throughput scales.

Reduced Glutamate Release in Adult BTBR Mouse Model of Autism Spectrum Disorder.

PubMed

Wei, Hongen; Ma, Yuehong; Ding, Caiyun; Jin, Guorong; Liu, Jianrong; Chang, Qiaoqiao; Hu, Fengyun; Yu, Li

2016-11-01

Autism spectrum disorder (ASD) is a developmental disorder characterized by impairments in social and communication abilities, as well as by restricted and repetitive behaviors. The BTBR T + Itpr3 tf (BTBR) mice have emerged as a well characterized and widely used mouse model of a range of ASD-like phenotype, showing deficiencies in social behaviors and unusual ultrasonic vocalizations as well as increased repetitive self-grooming. However, the inherited neurobiological changes that lead to ASD-like behaviors in these mice are incompletely known and still under active investigation. The aim of this study was to further evaluate the structure and neurotransmitter release of the glutamatergic synapse in BTBR mice. C57BL/6J (B6) mice were used as a control strain because of their high level of sociability. The important results showed that the evoked glutamate release in the cerebral cortex of BTBR mice was significantly lower than in B6 mice. And the level of vesicle docking-related protein Syntaxin-1A was reduced in BTBR mice. However, no significant changes were observed in the number of glutamatergic synapse, level of synaptic proteins, density of dendritic spine and postsynaptic density between BTBR mice and B6 mice. Overall, our results suggest that abnormal vesicular glutamate activity may underlie the ASD relevant pathology in the BTBR mice.

A lethal model of disseminated dengue virus type 1 infection in AG129 mice.

PubMed

Milligan, Gregg N; Sarathy, Vanessa V; White, Mellodee M; Greenberg, M Banks; Campbell, Gerald A; Pyles, Richard B; Barrett, Alan D T; Bourne, Nigel

2017-10-01

The mosquito-borne disease dengue is caused by four serologically and genetically related flaviviruses termed DENV-1 to DENV-4. Dengue is a global public health concern, with both the geographical range and burden of disease increasing rapidly. Clinically, dengue ranges from a relatively mild self-limiting illness to a severe life-threatening and sometimes fatal disease. Infection with one DENV serotype produces life-long homotypic immunity, but incomplete and short-term heterotypic protection. The development of small-animal models that recapitulate the characteristics of the disseminated disease seen clinically has been difficult, slowing the development of vaccines and therapeutics. The AG129 mouse (deficient in interferon alpha/beta and gamma receptor signalling) has proven to be valuable for this purpose, with the development of models of disseminated DENV-2,-3 and -4 disease. Recently, a DENV-1 AG129 model was described, but it requires antibody-dependent enhancement (ADE) to produce lethality. Here we describe a new AG129 model utilizing a non-mouse-adapted DENV-1 strain, West Pacific 74, that does not require ADE to induce lethal disease. Following high-titre intraperitoneal challenge, animals experience a virus infection with dissemination to multiple visceral tissues, including the liver, spleen and intestine. The animals also become thrombocytopenic, but vascular leakage is less prominent than in AG129 models with other DENV serotypes. Taken together, our studies demonstrate that this model is an important addition to dengue research, particularly for understanding the pathological basis of the disease between DENV serotypes and allowing the full spectrum of activity to test comparisons for putative vaccines and antivirals.

Identification of genes regulated during mechanical load-induced cardiac hypertrophy

NASA Technical Reports Server (NTRS)

Johnatty, S. E.; Dyck, J. R.; Michael, L. H.; Olson, E. N.; Abdellatif, M.; Schneider, M. (Principal Investigator)

2000-01-01

Cardiac hypertrophy is associated with both adaptive and adverse changes in gene expression. To identify genes regulated by pressure overload, we performed suppressive subtractive hybridization between cDNA from the hearts of aortic-banded (7-day) and sham-operated mice. In parallel, we performed a subtraction between an adult and a neonatal heart, for the purpose of comparing different forms of cardiac hypertrophy. Sequencing more than 100 clones led to the identification of an array of functionally known (70%) and unknown genes (30%) that are upregulated during cardiac growth. At least nine of those genes were preferentially expressed in both the neonatal and pressure over-load hearts alike. Using Northern blot analysis to investigate whether some of the identified genes were upregulated in the load-independent calcineurin-induced cardiac hypertrophy mouse model, revealed its incomplete similarity with the former models of cardiac growth. Copyright 2000 Academic Press.

A novel flexible cuff-like microelectrode for dual purpose, acute and chronic electrical interfacing with the mouse cervical vagus nerve

NASA Astrophysics Data System (ADS)

Caravaca, A. S.; Tsaava, T.; Goldman, L.; Silverman, H.; Riggott, G.; Chavan, S. S.; Bouton, C.; Tracey, K. J.; Desimone, R.; Boyden, E. S.; Sohal, H. S.; Olofsson, P. S.

2017-12-01

Objective. Neural reflexes regulate immune responses and homeostasis. Advances in bioelectronic medicine indicate that electrical stimulation of the vagus nerve can be used to treat inflammatory disease, yet the understanding of neural signals that regulate inflammation is incomplete. Current interfaces with the vagus nerve do not permit effective chronic stimulation or recording in mouse models, which is vital to studying the molecular and neurophysiological mechanisms that control inflammation homeostasis in health and disease. We developed an implantable, dual purpose, multi-channel, flexible ‘microelectrode’ array, for recording and stimulation of the mouse vagus nerve. Approach. The array was microfabricated on an 8 µm layer of highly biocompatible parylene configured with 16 sites. The microelectrode was evaluated by studying the recording and stimulation performance. Mice were chronically implanted with devices for up to 12 weeks. Main results. Using the microelectrode in vivo, high fidelity signals were recorded during physiological challenges (e.g potassium chloride and interleukin-1β), and electrical stimulation of the vagus nerve produced the expected significant reduction of blood levels of tumor necrosis factor (TNF) in endotoxemia. Inflammatory cell infiltration at the microelectrode 12 weeks of implantation was limited according to radial distribution analysis of inflammatory cells. Significance. This novel device provides an important step towards a viable chronic interface for cervical vagus nerve stimulation and recording in mice.

The Small GTPase Rif Is Dispensable for Platelet Filopodia Generation in Mice

PubMed Central

Goggs, Robert; Savage, Joshua S.; Mellor, Harry; Poole, Alastair W.

2013-01-01

Background Formation of filopodia and other shape change events are vital for platelet hemostatic function. The mechanisms regulating filopodia formation by platelets are incompletely understood however. In particular the small GTPase responsible for initiating filopodia formation by platelets remains elusive. The canonical pathway involving Cdc42 is not essential for filopodia formation in mouse platelets. The small GTPase Rif (RhoF) provides an alternative route to filopodia generation in other cell types and is expressed in both human and mouse platelets. Hypothesis/Objective We hypothesized that Rif might be responsible for generating filopodia by platelets and generated a novel knockout mouse model to investigate the functional role of Rif in platelets. Methodology/Principal Findings Constitutive RhoF−/− mice are viable and have normal platelet, leukocyte and erythrocyte counts and indices. RhoF−/− platelets form filopodia and spread normally on various agonist surfaces in static conditions and under arterial shear. In addition, RhoF−/− platelets have normal actin dynamics, are able to activate and aggregate normally and secrete from alpha and dense granules in response to collagen related peptide and thrombin stimulation. Conclusions The small GTPase Rif does not appear to be critical for platelet function in mice. Functional overlap between Rif and other small GTPases may be responsible for the non-essential role of Rif in platelets. PMID:23359340

OXPHOS-Mediated Induction of NAD+ Promotes Complete Oxidation of Fatty Acids and Interdicts Non-Alcoholic Fatty Liver Disease.

PubMed

Akie, Thomas E; Liu, Lijun; Nam, Minwoo; Lei, Shi; Cooper, Marcus P

2015-01-01

OXPHOS is believed to play an important role in non-alcoholic fatty liver disease (NAFLD), however, precise mechanisms whereby OXPHOS influences lipid homeostasis are incompletely understood. We previously reported that ectopic expression of LRPPRC, a protein that increases cristae density and OXPHOS, promoted fatty acid oxidation in cultured primary hepatocytes. To determine the biological significance of that observation and define underlying mechanisms, we have ectopically expressed LRPPRC in mouse liver in the setting of NAFLD. Interestingly, ectopic expression of LRPPRC in mouse liver completely interdicted NAFLD, including inflammation. Consistent with mitigation of NAFLD, two markers of hepatic insulin resistance--ROS and PKCε activity--were both modestly reduced. As reported by others, improvement of NAFLD was associated with improved whole-body insulin sensitivity. Regarding hepatic lipid homeostasis, the ratio of NAD+ to NADH was dramatically increased in mouse liver replete with LRPPRC. Pharmacological activators and inhibitors of the cellular respiration respectively increased and decreased the [NAD+]/[NADH] ratio, indicating respiration-mediated control of the [NAD+]/[NADH] ratio. Supporting a prominent role for NAD+, increasing the concentration of NAD+ stimulated complete oxidation of fatty acids. Importantly, NAD+ rescued impaired fatty acid oxidation in hepatocytes deficient for either OXPHOS or SIRT3. These data are consistent with a model whereby augmented hepatic OXPHOS increases NAD+, which in turn promotes complete oxidation of fatty acids and protects against NAFLD.

High-throughput discovery of novel developmental phenotypes

PubMed Central

Dickinson, Mary E.; Flenniken, Ann M.; Ji, Xiao; Teboul, Lydia; Wong, Michael D.; White, Jacqueline K.; Meehan, Terrence F.; Weninger, Wolfgang J.; Westerberg, Henrik; Adissu, Hibret; Baker, Candice N.; Bower, Lynette; Brown, James M.; Caddle, L. Brianna; Chiani, Francesco; Clary, Dave; Cleak, James; Daly, Mark J.; Denegre, James M.; Doe, Brendan; Dolan, Mary E.; Edie, Sarah M.; Fuchs, Helmut; Gailus-Durner, Valerie; Galli, Antonella; Gambadoro, Alessia; Gallegos, Juan; Guo, Shiying; Horner, Neil R.; Hsu, Chih-wei; Johnson, Sara J.; Kalaga, Sowmya; Keith, Lance C.; Lanoue, Louise; Lawson, Thomas N.; Lek, Monkol; Mark, Manuel; Marschall, Susan; Mason, Jeremy; McElwee, Melissa L.; Newbigging, Susan; Nutter, Lauryl M.J.; Peterson, Kevin A.; Ramirez-Solis, Ramiro; Rowland, Douglas J.; Ryder, Edward; Samocha, Kaitlin E.; Seavitt, John R.; Selloum, Mohammed; Szoke-Kovacs, Zsombor; Tamura, Masaru; Trainor, Amanda G; Tudose, Ilinca; Wakana, Shigeharu; Warren, Jonathan; Wendling, Olivia; West, David B.; Wong, Leeyean; Yoshiki, Atsushi; MacArthur, Daniel G.; Tocchini-Valentini, Glauco P.; Gao, Xiang; Flicek, Paul; Bradley, Allan; Skarnes, William C.; Justice, Monica J.; Parkinson, Helen E.; Moore, Mark; Wells, Sara; Braun, Robert E.; Svenson, Karen L.; de Angelis, Martin Hrabe; Herault, Yann; Mohun, Tim; Mallon, Ann-Marie; Henkelman, R. Mark; Brown, Steve D.M.; Adams, David J.; Lloyd, K.C. Kent; McKerlie, Colin; Beaudet, Arthur L.; Bucan, Maja; Murray, Stephen A.

2016-01-01

Approximately one third of all mammalian genes are essential for life. Phenotypes resulting from mouse knockouts of these genes have provided tremendous insight into gene function and congenital disorders. As part of the International Mouse Phenotyping Consortium effort to generate and phenotypically characterize 5000 knockout mouse lines, we have identified 410 lethal genes during the production of the first 1751 unique gene knockouts. Using a standardised phenotyping platform that incorporates high-resolution 3D imaging, we identified novel phenotypes at multiple time points for previously uncharacterized genes and additional phenotypes for genes with previously reported mutant phenotypes. Unexpectedly, our analysis reveals that incomplete penetrance and variable expressivity are common even on a defined genetic background. In addition, we show that human disease genes are enriched for essential genes identified in our screen, thus providing a novel dataset that facilitates prioritization and validation of mutations identified in clinical sequencing efforts. PMID:27626380

A preclinical orthotopic model for glioblastoma recapitulates key features of human tumors and demonstrates sensitivity to a combination of MEK and PI3K pathway inhibitors.

PubMed

El Meskini, Rajaa; Iacovelli, Anthony J; Kulaga, Alan; Gumprecht, Michelle; Martin, Philip L; Baran, Maureen; Householder, Deborah B; Van Dyke, Terry; Weaver Ohler, Zoë

2015-01-01

Current therapies for glioblastoma multiforme (GBM), the highest grade malignant brain tumor, are mostly ineffective, and better preclinical model systems are needed to increase the successful translation of drug discovery efforts into the clinic. Previous work describes a genetically engineered mouse (GEM) model that contains perturbations in the most frequently dysregulated networks in GBM (driven by RB, KRAS and/or PI3K signaling and PTEN) that induce development of Grade IV astrocytoma with properties of the human disease. Here, we developed and characterized an orthotopic mouse model derived from the GEM that retains the features of the GEM model in an immunocompetent background; however, this model is also tractable and efficient for preclinical evaluation of candidate therapeutic regimens. Orthotopic brain tumors are highly proliferative, invasive and vascular, and express histology markers characteristic of human GBM. Primary tumor cells were examined for sensitivity to chemotherapeutics and targeted drugs. PI3K and MAPK pathway inhibitors, when used as single agents, inhibited cell proliferation but did not result in significant apoptosis. However, in combination, these inhibitors resulted in a substantial increase in cell death. Moreover, these findings translated into the in vivo orthotopic model: PI3K or MAPK inhibitor treatment regimens resulted in incomplete pathway suppression and feedback loops, whereas dual treatment delayed tumor growth through increased apoptosis and decreased tumor cell proliferation. Analysis of downstream pathway components revealed a cooperative effect on target downregulation. These concordant results, together with the morphologic similarities to the human GBM disease characteristics of the model, validate it as a new platform for the evaluation of GBM treatment. © 2015. Published by The Company of Biologists Ltd.

A preclinical orthotopic model for glioblastoma recapitulates key features of human tumors and demonstrates sensitivity to a combination of MEK and PI3K pathway inhibitors

PubMed Central

El Meskini, Rajaa; Iacovelli, Anthony J.; Kulaga, Alan; Gumprecht, Michelle; Martin, Philip L.; Baran, Maureen; Householder, Deborah B.; Van Dyke, Terry; Weaver Ohler, Zoë

2015-01-01

Current therapies for glioblastoma multiforme (GBM), the highest grade malignant brain tumor, are mostly ineffective, and better preclinical model systems are needed to increase the successful translation of drug discovery efforts into the clinic. Previous work describes a genetically engineered mouse (GEM) model that contains perturbations in the most frequently dysregulated networks in GBM (driven by RB, KRAS and/or PI3K signaling and PTEN) that induce development of Grade IV astrocytoma with properties of the human disease. Here, we developed and characterized an orthotopic mouse model derived from the GEM that retains the features of the GEM model in an immunocompetent background; however, this model is also tractable and efficient for preclinical evaluation of candidate therapeutic regimens. Orthotopic brain tumors are highly proliferative, invasive and vascular, and express histology markers characteristic of human GBM. Primary tumor cells were examined for sensitivity to chemotherapeutics and targeted drugs. PI3K and MAPK pathway inhibitors, when used as single agents, inhibited cell proliferation but did not result in significant apoptosis. However, in combination, these inhibitors resulted in a substantial increase in cell death. Moreover, these findings translated into the in vivo orthotopic model: PI3K or MAPK inhibitor treatment regimens resulted in incomplete pathway suppression and feedback loops, whereas dual treatment delayed tumor growth through increased apoptosis and decreased tumor cell proliferation. Analysis of downstream pathway components revealed a cooperative effect on target downregulation. These concordant results, together with the morphologic similarities to the human GBM disease characteristics of the model, validate it as a new platform for the evaluation of GBM treatment. PMID:25431423

Inferring the Impact of Regulatory Mechanisms that Underpin CD8+ T Cell Control of B16 Tumor Growth In vivo Using Mechanistic Models and Simulation.

PubMed

Klinke, David J; Wang, Qing

2016-01-01

A major barrier for broadening the efficacy of immunotherapies for cancer is identifying key mechanisms that limit the efficacy of tumor infiltrating lymphocytes. Yet, identifying these mechanisms using human samples and mouse models for cancer remains a challenge. While interactions between cancer and the immune system are dynamic and non-linear, identifying the relative roles that biological components play in regulating anti-tumor immunity commonly relies on human intuition alone, which can be limited by cognitive biases. To assist natural intuition, modeling and simulation play an emerging role in identifying therapeutic mechanisms. To illustrate the approach, we developed a multi-scale mechanistic model to describe the control of tumor growth by a primary response of CD8+ T cells against defined tumor antigens using the B16 C57Bl/6 mouse model for malignant melanoma. The mechanistic model was calibrated to data obtained following adenovirus-based immunization and validated to data obtained following adoptive transfer of transgenic CD8+ T cells. More importantly, we use simulation to test whether the postulated network topology, that is the modeled biological components and their associated interactions, is sufficient to capture the observed anti-tumor immune response. Given the available data, the simulation results also provided a statistical basis for quantifying the relative importance of different mechanisms that underpin CD8+ T cell control of B16F10 growth. By identifying conditions where the postulated network topology is incomplete, we illustrate how this approach can be used as part of an iterative design-build-test cycle to expand the predictive power of the model.

CD8+IL-17+ T Cells Mediate Neutrophilic Airway Obliteration in T-bet–Deficient Mouse Lung Allograft Recipients

PubMed Central

Dodd-o, Jeffrey M.; Coon, Tiffany A.; Miller, Hannah L.; Ganguly, Sudipto; Popescu, Iulia; O'Donnell, Christopher P.; Cardenes, Nayra; Levine, Melanie; Rojas, Mauricio; Weathington, Nathaniel M.; Zhao, Jing; Zhao, Yutong; McDyer, John F.

2015-01-01

Acute cellular rejection is a known risk factor for the development of obliterative bronchiolitis, which limits the long-term survival of lung transplant recipients. However, the T cell effector mechanisms in both of these processes remain incompletely understood. Using the mouse orthotopic lung transplant model, we investigated whether C57BL/6 T-bet−/− recipients of major histocompatibility complex (MHC)-mismatched BALB/c lung grafts develop rejection pathology and allospecific cytokine responses that differ from wild-type mice. T-bet−/− recipients demonstrated vigorous allograft rejection at 10 days, characterized by neutrophilic inflammation and predominantly CD8+ T cells producing allospecific IL-17 and/or IFN-γ, in contrast to IFN-γ–dominant responses in WT mice. CD4+ T cells produced IL-17 but not IFN-γ responses in T-bet−/− recipients, in contrast to WT controls. Costimulation blockade using anti-CD154 Ab significantly reduced allospecific CD8+IFN-γ+ responses in both T-bet−/− and WT mice but had no attenuating effect on lung rejection pathology in T-bet−/− recipients or on the development of obliterative airway inflammation that occurred only in T-bet−/− recipients. However, neutralization of IL-17A significantly attenuated costimulation blockade–resistant rejection pathology and airway inflammation in T-bet−/− recipients. In addition, CXCL1 (neutrophil chemokine) was increased in T-bet−/− allografts, and IL-17 induced CXCL1 from mouse lung epithelial cells in vitro. Taken together, our data show that T-bet–deficient recipients of complete MHC-mismatched lung allografts develop costimulation blockade–resistant rejection characterized by neutrophilia and obliterative airway inflammation that is predominantly mediated by CD8+IL-17+ T cells. Our data support T-bet–deficient mouse recipients of lung allografts as a viable animal model to study the immunopathogenesis of small airway injury in lung transplantation. PMID:25286244

eGFP expression under the Uchl1 promoter labels corticospinal motor neurons and a subpopulation of degeneration resistant spinal motor neurons in ALS mouse models

NASA Astrophysics Data System (ADS)

Yasvoina, Marina V.

Current understanding of basic cellular and molecular mechanisms for motor neuron vulnerability during motor neuron disease initiation and progression is incomplete. The complex cytoarchitecture and cellular heterogeneity of the cortex and spinal cord greatly impedes our ability to visualize, isolate, and study specific neuron populations in both healthy and diseased states. We generated a novel reporter line, the Uchl1-eGFP mouse, in which cortical and spinal components of motor neuron circuitry are genetically labeled with eGFP under the Uchl1 promoter. A series of cellular and anatomical analyses combined with retrograde labeling, molecular marker expression, and electrophysiology were employed to determine identity of eGFP expressing cells in the motor cortex and the spinal cord of novel Uchl1-eGFP reporter mice. We conclude that eGFP is expressed in corticospinal motor neurons (CSMN) in the motor cortex and a subset of S-type alpha and gamma spinal motor neurons (SMN) in the spinal cord. hSOD1G93A and Alsin-/- mice, mouse models for amyotrophic lateral sclerosis (ALS), were bred to Uchl1-eGFP reporter mouse line to investigate the pathophysiology and underlying mechanisms of CSMN degeneration in vivo. Evidence suggests early and progressive degeneration of CSMN and SMN in the hSOD1G93A transgenic mice. We show an early increase of autophagosome formation in the apical dendrites of vulnerable CSMN in hSOD1G93A-UeGFP mice, which is localized to the apical dendrites. In addition, labeling S-type alpha and gamma SMN in the hSOD1G93A-UeGFP mice provide a unique opportunity to study basis of their resistance to degeneration. Mice lacking alsin show moderate clinical phenotype and mild CSMN axon degeneration in the spinal cord, which suggests vulnerability of CSMN. Therefore, we investigated the CSMN cellular and axon defects in aged Alsin-/- mice bred to Uchl1-eGFP reporter mouse line. We show that while CSMN are preserved and lack signs of degeneration, CSMN axons are vulnerable and show significant loss.

JMJD1C Ensures Mouse Embryonic Stem Cell Self-Renewal and Somatic Cell Reprogramming through Controlling MicroRNA Expression.

PubMed

Xiao, Feng; Liao, Bing; Hu, Jing; Li, Shuang; Zhao, Haixin; Sun, Ming; Gu, Junjie; Jin, Ying

2017-09-12

The roles of histone demethylases (HDMs) for the establishment and maintenance of pluripotency are incompletely characterized. Here, we show that JmjC-domain-containing protein 1c (JMJD1C), an H3K9 demethylase, is required for mouse embryonic stem cell (ESC) self-renewal. Depletion of Jmjd1c leads to the activation of ERK/MAPK signaling and epithelial-to-mesenchymal transition (EMT) to induce differentiation of ESCs. Inhibition of ERK/MAPK signaling rescues the differentiation phenotype caused by Jmjd1c depletion. Mechanistically, JMJD1C, with the help of pluripotency factor KLF4, maintains ESC identity at least in part by regulating the expression of the miR-200 family and miR-290/295 cluster to suppress the ERK/MAPK signaling and EMT. Additionally, we uncover that JMJD1C ensures efficient generation and maintenance of induced pluripotent stem cells, at least partially through controlling the expression of microRNAs. Collectively, we propose an integrated model of epigenetic and transcriptional control mediated by the H3K9 demethylase for ESC self-renewal and somatic cell reprogramming. Copyright © 2017 The Authors. Published by Elsevier Inc. All rights reserved.

Cardiac Niche Influences the Direct Reprogramming of Canine Fibroblasts into Cardiomyocyte-Like Cells

PubMed Central

Palazzolo, Giacomo; Quattrocelli, Mattia; Toelen, Jaan; Dominici, Roberto; Tettamenti, Guido; Barthelemy, Inès; Blot, Stephane; Gijsbers, Rik; Cassano, Marco

2016-01-01

The Duchenne and Becker muscular dystrophies are caused by mutation of dystrophin gene and primarily affect skeletal and cardiac muscles. Cardiac involvement in dystrophic GRMD dogs has been demonstrated by electrocardiographic studies with the onset of a progressive cardiomyopathy similar to the cardiac disease in DMD patients. In this respect, GRMD is a useful model to explore cardiac and skeletal muscle pathogenesis and for developing new therapeutic protocols. Here we describe a protocol to convert GRMD canine fibroblasts isolated from heart and skin into induced cardiac-like myocytes (ciCLMs). We used a mix of transcription factors (GATA4, HAND2, TBX5, and MEF2C), known to be able to differentiate mouse and human somatic cells into ciCLMs. Exogenous gene expression was obtained using four lentiviral vectors carrying transcription factor genes and different resistance genes. Our data demonstrate a direct switch from fibroblast into ciCLMs with no activation of early cardiac genes. ciCLMs were unable to contract spontaneously, suggesting, differently from mouse and human cells, an incomplete differentiation process. However, when transplanted in neonatal hearts of SCID/Beige mice, ciCLMs participate in cardiac myogenesis. PMID:26681949

Cardiac Niche Influences the Direct Reprogramming of Canine Fibroblasts into Cardiomyocyte-Like Cells.

PubMed

Palazzolo, Giacomo; Quattrocelli, Mattia; Toelen, Jaan; Dominici, Roberto; Anastasia, Luigi; Tettamenti, Guido; Barthelemy, Inès; Blot, Stephane; Gijsbers, Rik; Cassano, Marco; Sampaolesi, Maurilio

2016-01-01

The Duchenne and Becker muscular dystrophies are caused by mutation of dystrophin gene and primarily affect skeletal and cardiac muscles. Cardiac involvement in dystrophic GRMD dogs has been demonstrated by electrocardiographic studies with the onset of a progressive cardiomyopathy similar to the cardiac disease in DMD patients. In this respect, GRMD is a useful model to explore cardiac and skeletal muscle pathogenesis and for developing new therapeutic protocols. Here we describe a protocol to convert GRMD canine fibroblasts isolated from heart and skin into induced cardiac-like myocytes (ciCLMs). We used a mix of transcription factors (GATA4, HAND2, TBX5, and MEF2C), known to be able to differentiate mouse and human somatic cells into ciCLMs. Exogenous gene expression was obtained using four lentiviral vectors carrying transcription factor genes and different resistance genes. Our data demonstrate a direct switch from fibroblast into ciCLMs with no activation of early cardiac genes. ciCLMs were unable to contract spontaneously, suggesting, differently from mouse and human cells, an incomplete differentiation process. However, when transplanted in neonatal hearts of SCID/Beige mice, ciCLMs participate in cardiac myogenesis.

Hepatocyte nuclear receptor SHP suppresses inflammation and fibrosis in a mouse model of nonalcoholic steatohepatitis.

PubMed

Zou, An; Magee, Nancy; Deng, Fengyan; Lehn, Sarah; Zhong, Cuncong; Zhang, Yuxia

2018-06-01

Nonalcoholic fatty liver disease (NAFLD) is a burgeoning health problem worldwide, ranging from nonalcoholic fatty liver (NAFL, steatosis without hepatocellular injury) to the more aggressive nonalcoholic steatohepatitis (NASH, steatosis with ballooning, inflammation, or fibrosis). Although many studies have greatly contributed to the elucidation of NAFLD pathogenesis, the disease progression from NAFL to NASH remains incompletely understood. Nuclear receptor small heterodimer partner (Nr0b2, SHP ) is a transcriptional regulator critical for the regulation of bile acid, glucose, and lipid metabolism. Here, we show that SHP levels are decreased in the livers of patients with NASH and in diet-induced mouse NASH. Exposing primary mouse hepatocytes to palmitic acid and lipopolysaccharide in vitro , we demonstrated that the suppression of Shp expression in hepatocytes is due to c-Jun N-terminal kinase (JNK) activation, which stimulates c-Jun-mediated transcriptional repression of Shp Interestingly, in vivo induction of hepatocyte-specific SHP in steatotic mouse liver ameliorated NASH progression by attenuating liver inflammation and fibrosis, but not steatosis. Moreover, a key mechanism linking the anti-inflammatory role of hepatocyte-specific SHP expression to inflammation involved SHP-induced suppression of NF-κB p65-mediated induction of chemokine (C-C motif) ligand 2 (CCL2), which activates macrophage proinflammatory polarization and migration. In summary, our results indicate that a JNK/SHP/NF-κB/CCL2 regulatory network controls communications between hepatocytes and macrophages and contributes to the disease progression from NAFL to NASH. Our findings may benefit the development of new management or prevention strategies for NASH. © 2018 by The American Society for Biochemistry and Molecular Biology, Inc.

Detection of DNA Double Strand Breaks by γH2AX Does Not Result in 53bp1 Recruitment in Mouse Retinal Tissues

PubMed Central

Müller, Brigitte; Ellinwood, N. M.; Lorenz, Birgit; Stieger, Knut

2018-01-01

Gene editing is an attractive potential treatment of inherited retinopathies. However, it often relies on endogenous DNA repair. Retinal DNA repair is incompletely characterized in humans and animal models. We investigated recruitment of the double stranded break (DSB) repair complex of γH2AX and 53bp1 in both developing and mature mouse neuroretinas. We evaluated the immunofluorescent retinal expression of these proteins during development (P07-P30) in normal and retinal degeneration models, as well as in potassium bromate induced DSB repair in normal adult (3 months) retinal explants. The two murine retinopathy models used had different mutations in Pde6b: the severe rd1 and the milder rd10 models. Compared to normal adult retina, we found increased numbers of γH2AX positive foci in all retinal neurons of the developing retina in both model and control retinas, as well as in wild type untreated retinal explant cultures. In contrast, the 53bp1 staining of the retina differed both in amount and character between cell types at all ages and in all model systems. There was strong pan nuclear staining in ganglion, amacrine, and horizontal cells, and cone photoreceptors, which was attenuated. Rod photoreceptors did not stain unequivocally. In all samples, 53bp1 stained foci only rarely occurred. Co-localization of 53bp1 and γH2AX staining was a very rare event (< 1% of γH2AX foci in the ONL and < 3% in the INL), suggesting the potential for alternate DSB sensing and repair proteins in the murine retina. At a minimum, murine retinal DSB repair does not appear to follow canonical pathways, and our findings suggests further investigation is warranted. PMID:29765300

Weight Loss Decreases Inherent and Allergic Methacholine Hyperresponsiveness in Mouse Models of Diet-Induced Obese Asthma

PubMed Central

Ather, Jennifer L.; Chung, Michael; Hoyt, Laura R.; Randall, Matthew J.; Georgsdottir, Anna; Daphtary, Nirav A.; Aliyeva, Minara I.; Suratt, Benjamin T.; Bates, Jason H. T.; Irvin, Charles G.; Russell, Sheila R.; Forgione, Patrick M.; Dixon, Anne E.

2016-01-01

Obese asthma presents with inherent hyperresponsiveness to methacholine or augmented allergen-driven allergic asthma, with an even greater magnitude of methacholine hyperresponsiveness. These physiologic parameters and accompanying obese asthma symptoms can be reduced by successful weight loss, yet the underlying mechanisms remain incompletely understood. We implemented mouse models of diet-induced obesity, dietary and surgical weight loss, and environmental allergen exposure to examine the mechanisms and mediators of inherent and allergic obese asthma. We report that the methacholine hyperresponsiveness in these models of inherent obese asthma and obese allergic asthma manifests in distinct anatomical compartments but that both are amenable to interventions that induce substantial weight loss. The inherent obese asthma phenotype, with characteristic increases in distal airspace tissue resistance and tissue elastance, is associated with elevated proinflammatory cytokines that are reduced with dietary weight loss. Surprisingly, bariatric surgery–induced weight loss further elevates these cytokines while reducing methacholine responsiveness to levels similar to those in lean mice or in formerly obese mice rendered lean through dietary intervention. In contrast, the obese allergic asthma phenotype, with characteristic increases in central airway resistance, is not associated with increased adaptive immune responses, yet diet-induced weight loss reduces methacholine hyperresponsiveness without altering immunological variables. Diet-induced weight loss is effective in models of both inherent and allergic obese asthma, and our examination of the fecal microbiome revealed that the obesogenic Firmicutes/Bacteroidetes ratio was normalized after diet-induced weight loss. Our results suggest that structural, immunological, and microbiological factors contribute to the manifold presentations of obese asthma. PMID:27064658

Involvement of Atm and Trp53 in neural cell loss due to Terf2 inactivation during mouse brain development.

PubMed

Kim, Jusik; Choi, Inseo; Lee, Youngsoo

2017-11-01

Maintenance of genomic integrity is one of the critical features for proper neurodevelopment and inhibition of neurological diseases. The signals from both ATM and ATR to TP53 are well-known mechanisms to remove neural cells with DNA damage during neurogenesis. Here we examined the involvement of Atm and Atr in genomic instability due to Terf2 inactivation during mouse brain development. Selective inactivation of Terf2 in neural progenitors induced apoptosis, resulting in a complete loss of the brain structure. This neural loss was rescued partially in both Atm and Trp53 deficiency, but not in an Atr-deficient background in the mouse. Atm inactivation resulted in incomplete brain structures, whereas p53 deficiency led to the formation of multinucleated giant neural cells and the disruption of the brain structure. These giant neural cells disappeared in Lig4 deficiency. These data demonstrate ATM and TP53 are important for the maintenance of telomere homeostasis and the surveillance of telomere dysfunction during neurogenesis.

Human Anti-Plague Monoclonal Antibodies Protect Mice from Yersinia pestis in a Bubonic Plague Model

PubMed Central

Xiao, Xiaodong; Zhu, Zhongyu; Dankmeyer, Jennifer L.; Wormald, Michael M.; Fast, Randy L.; Worsham, Patricia L.; Cote, Christopher K.; Amemiya, Kei; Dimitrov, Dimiter S.

2010-01-01

Yersinia pestis is the etiologic agent of plague that has killed more than 200 million people throughout the recorded history of mankind. Antibiotics may provide little immediate relief to patients who have a high bacteremia or to patients infected with an antibiotic resistant strain of plague. Two virulent factors of Y. pestis are the capsid F1 protein and the low-calcium response (Lcr) V-protein or V-antigen that have been proven to be the targets for both active and passive immunization. There are mouse monoclonal antibodies (mAbs) against the F1- and V-antigens that can passively protect mice in a murine model of plague; however, there are no anti-Yersinia pestis monoclonal antibodies available for prophylactic or therapeutic treatment in humans. We identified one anti-F1-specific human mAb (m252) and two anti-V-specific human mAb (m253, m254) by panning a naïve phage-displayed Fab library against the F1- and V-antigens. The Fabs were converted to IgG1s and their binding and protective activities were evaluated. M252 bound weakly to peptides located at the F1 N-terminus where a protective mouse anti-F1 mAb also binds. M253 bound strongly to a V-antigen peptide indicating a linear epitope; m254 did not bind to any peptide from a panel of 53 peptides suggesting that its epitope may be conformational. M252 showed better protection than m253 and m254 against a Y, pestis challenge in a plague mouse model. A synergistic effect was observed when the three antibodies were combined. Incomplete to complete protection was achieved when m252 was given at different times post-challenge. These antibodies can be further studied to determine their potential as therapeutics or prophylactics in Y. pestis infection in humans. PMID:20976274

Human anti-plague monoclonal antibodies protect mice from Yersinia pestis in a bubonic plague model.

PubMed

Xiao, Xiaodong; Zhu, Zhongyu; Dankmeyer, Jennifer L; Wormald, Michael M; Fast, Randy L; Worsham, Patricia L; Cote, Christopher K; Amemiya, Kei; Dimitrov, Dimiter S

2010-10-13

Yersinia pestis is the etiologic agent of plague that has killed more than 200 million people throughout the recorded history of mankind. Antibiotics may provide little immediate relief to patients who have a high bacteremia or to patients infected with an antibiotic resistant strain of plague. Two virulent factors of Y. pestis are the capsid F1 protein and the low-calcium response (Lcr) V-protein or V-antigen that have been proven to be the targets for both active and passive immunization. There are mouse monoclonal antibodies (mAbs) against the F1- and V-antigens that can passively protect mice in a murine model of plague; however, there are no anti-Yersinia pestis monoclonal antibodies available for prophylactic or therapeutic treatment in humans. We identified one anti-F1-specific human mAb (m252) and two anti-V-specific human mAb (m253, m254) by panning a naïve phage-displayed Fab library against the F1- and V-antigens. The Fabs were converted to IgG1s and their binding and protective activities were evaluated. M252 bound weakly to peptides located at the F1 N-terminus where a protective mouse anti-F1 mAb also binds. M253 bound strongly to a V-antigen peptide indicating a linear epitope; m254 did not bind to any peptide from a panel of 53 peptides suggesting that its epitope may be conformational. M252 showed better protection than m253 and m254 against a Y, pestis challenge in a plague mouse model. A synergistic effect was observed when the three antibodies were combined. Incomplete to complete protection was achieved when m252 was given at different times post-challenge. These antibodies can be further studied to determine their potential as therapeutics or prophylactics in Y. pestis infection in humans.

Failsafe modes in incomplete minority game

NASA Astrophysics Data System (ADS)

Yao, Xiaobo; Wan, Shaolong; Chen, Wen

2009-09-01

We make a failsafe extension to the incomplete minority game model, give a brief analysis on how incompleteness will effect system efficiency. Simulations that limited incompleteness in strategies can improve the system efficiency. Among three failsafe modes, the “Back-to-Best” mode brings most significant improvement and keeps the system efficiency in a long range of incompleteness. A simple analytic formula has a trend which matches simulation results. The IMMG model is used to study the effect of distribution, and we find that there is one junction point in each series of curves, at which system efficiency is not influenced by the distribution of incompleteness. When pIbar > the concentration of incompleteness weakens the effect. On the other side of , concentration will be helpful. When pI is close to zero agents using incomplete strategies have on average better profits than those using standard strategies, and the “Back-to-Best” agents have a wider range of pI to win.

Effects of unconventional breakup modes on incomplete fusion of weakly bound nuclei

NASA Astrophysics Data System (ADS)

Diaz-Torres, Alexis; Quraishi, Daanish

2018-02-01

The incomplete fusion dynamics of 6Li+209Bi collisions at energies above the Coulomb barrier is investigated. The classical dynamical model implemented in the platypus code is used to understand and quantify the impact of both 6Li resonance states and transfer-triggered breakup modes (involving short-lived projectile-like nuclei such as 8Be and 5Li) on the formation of incomplete fusion products. Model calculations explain the experimental incomplete-fusion excitation function fairly well, indicating that (i) delayed direct breakup of 6Li reduces the incomplete fusion cross sections and (ii) the neutron-stripping channel practically determines those cross sections.

Nuclear lamina defects cause ATM-dependent NF-κB activation and link accelerated aging to a systemic inflammatory response.

PubMed

Osorio, Fernando G; Bárcena, Clea; Soria-Valles, Clara; Ramsay, Andrew J; de Carlos, Félix; Cobo, Juan; Fueyo, Antonio; Freije, José M P; López-Otín, Carlos

2012-10-15

Alterations in the architecture and dynamics of the nuclear lamina have a causal role in normal and accelerated aging through both cell-autonomous and systemic mechanisms. However, the precise nature of the molecular cues involved in this process remains incompletely defined. Here we report that the accumulation of prelamin A isoforms at the nuclear lamina triggers an ATM- and NEMO-dependent signaling pathway that leads to NF-κB activation and secretion of high levels of proinflammatory cytokines in two different mouse models of accelerated aging (Zmpste24(-/-) and Lmna(G609G/G609G) mice). Causal involvement of NF-κB in accelerated aging was demonstrated by the fact that both genetic and pharmacological inhibition of NF-κB signaling prevents age-associated features in these animal models, significantly extending their longevity. Our findings provide in vivo proof of principle for the feasibility of pharmacological modulation of the NF-κB pathway to slow down the progression of physiological and pathological aging.

Neurotensin increases mortality and mast cells reduce neurotensin levels in a mouse model of sepsis.

PubMed

Piliponsky, Adrian M; Chen, Ching-Cheng; Nishimura, Toshihiko; Metz, Martin; Rios, Eon J; Dobner, Paul R; Wada, Etsuko; Wada, Keiji; Zacharias, Sherma; Mohanasundaram, Uma M; Faix, James D; Abrink, Magnus; Pejler, Gunnar; Pearl, Ronald G; Tsai, Mindy; Galli, Stephen J

2008-04-01

Sepsis is a complex, incompletely understood and often fatal disorder, typically accompanied by hypotension, that is considered to represent a dysregulated host response to infection. Neurotensin (NT) is a 13-amino-acid peptide that, among its multiple effects, induces hypotension. We find that intraperitoneal and plasma concentrations of NT are increased in mice after severe cecal ligation and puncture (CLP), a model of sepsis, and that mice treated with a pharmacological antagonist of NT, or NT-deficient mice, show reduced mortality during severe CLP. In mice, mast cells can degrade NT and reduce NT-induced hypotension and CLP-associated mortality, and optimal expression of these effects requires mast cell expression of neurotensin receptor 1 and neurolysin. These findings show that NT contributes to sepsis-related mortality in mice during severe CLP and that mast cells can lower NT concentrations, and suggest that mast cell-dependent reduction in NT levels contributes to the ability of mast cells to enhance survival after CLP.

Incomplete lung recovery following sub-acute inhalation of combustion-derived ultrafine particles in mice.

PubMed

Noël, A; Xiao, R; Perveen, Z; Zaman, H M; Rouse, R L; Paulsen, D B; Penn, A L

2016-02-24

Particulate matter (PM) is one of the six criteria pollutant classes for which National Ambient Air Quality Standards have been set by the United States Environmental Protection Agency. Exposures to PM have been correlated with increased cardio-pulmonary morbidity and mortality. Butadiene soot (BDS), generated from the incomplete combustion of 1,3-butadiene (BD), is both a model PM mixture and a real-life example of a petrochemical product of incomplete combustion. There are numerous events, including wildfires, accidents at refineries and tank car explosions that result in sub-acute exposure to high levels of airborne particles, with the people exposed facing serious health problems. These real-life events highlight the need to investigate the health effects induced by short-term exposure to elevated levels of PM, as well as to assess whether, and if so, how well these adverse effects are resolved over time. In the present study, we investigated the extent of recovery of mouse lungs 10 days after inhalation exposures to environmentally-relevant levels of BDS aerosols had ended. Female BALB/c mice exposed to either HEPA-filtered air or to BDS (5 mg/m(3) in HEPA filtered air, 4 h/day, 21 consecutive days) were sacrificed immediately, or 10 days after the final BDS exposure. Bronchoalveolar lavage fluid (BALF) was collected for cytology and cytokine analysis. Lung proteins and RNA were extracted for protein and gene expression analysis. Lung histopathology evaluation also was performed. Sub-acute exposures of mice to hydrocarbon-rich ultrafine particles induced: (1) BALF neutrophil elevation; (2) lung mucosal inflammation, and (3) increased BALF IL-1β concentration; with all three outcomes returning to baseline levels 10 days post-exposure. In contrast, (4) lung connective tissue inflammation persisted 10 days post-exposure; (5) we detected time-dependent up-regulation of biotransformation and oxidative stress genes, with incomplete return to baseline levels; and (6) we observed persistent particle alveolar load following 10 days of recovery. These data show that 10 days after a 21-day exposure to 5 mg/m(3) of BDS has ended, incomplete lung recovery promotes a pro-biotransformation, pro-oxidant, and pro-inflammatory milieu, which may be a starting point for potential long-term cardio-pulmonary effects.

Effects of lithium chloride as a potential radioprotective agent on radiation response of DNA synthesis in mouse germinal cells.

PubMed

Bhattacharjee, D; Rajan, R; Krishnamoorthy, L; Singh, B B

1997-06-01

Mouse spermatogonial germ cells are highly sensitive to ionizing radiation. Lithium salts are reported to stimulate the postirradiation recovery of hematopoietic marrow cells. We have, therefore, examined whether administered lithium chloride (LiCl) would also be able to protect the mouse germinal cells against radiation injury. Taking DNA synthesis as an endpoint, our results show that the testicular DNA-specific activity in irradiated mice was higher by 61% on average when they had been pretreated with LiCl both 24 h and 1 h prior to gamma-irradiation (2.0 Gy). It was also observed that the DNA synthetic activity in the germinal cells fully recovered after LiCl pretreatment at doses of 40 mg per kg body weight prior to total body irradiation of 0.05-0.25 Gy, whereas at doses of 0.5-6.0 Gy, following the same procedure of LiCl pretreatment, only an incomplete recovery was observed. The dose reduction factor for LiCl is 1.84. The current findings indicate that pretreatment with LiCl provides considerable protection against radiation damage in mouse spermatogonia.

Multi-level omics analysis in a murine model of dystrophin loss and therapeutic restoration.

PubMed

Roberts, Thomas C; Johansson, Henrik J; McClorey, Graham; Godfrey, Caroline; Blomberg, K Emelie M; Coursindel, Thibault; Gait, Michael J; Smith, C I Edvard; Lehtiö, Janne; El Andaloussi, Samir; Wood, Matthew J A

2015-12-01

Duchenne muscular dystrophy (DMD) is a classical monogenic disorder, a model disease for genomic studies and a priority candidate for regenerative medicine and gene therapy. Although the genetic cause of DMD is well known, the molecular pathogenesis of disease and the response to therapy are incompletely understood. Here, we describe analyses of protein, mRNA and microRNA expression in the tibialis anterior of the mdx mouse model of DMD. Notably, 3272 proteins were quantifiable and 525 identified as differentially expressed in mdx muscle (P < 0.01). Therapeutic restoration of dystrophin by exon skipping induced widespread shifts in protein and mRNA expression towards wild-type expression levels, whereas the miRNome was largely unaffected. Comparison analyses between datasets showed that protein and mRNA ratios were only weakly correlated (r = 0.405), and identified a multitude of differentially affected cellular pathways, upstream regulators and predicted miRNA-target interactions. This study provides fundamental new insights into gene expression and regulation in dystrophic muscle. © The Author 2015. Published by Oxford University Press.

Fluoxetine maintains a state of heightened responsiveness to motor training early after stroke in a mouse model

PubMed Central

Ng, Kwan; Gibson, Ellen M.; Hubbard, Robert; Yang, Juemin; Caffo, Brian; O’Brien, Richard; Krakauer, John W.; Zeiler, Steven R.

2016-01-01

Background and purpose Data from both humans and animal models suggest that most recovery from motor impairment occurs in a sensitive period that lasts only weeks after stroke and is mediated in part by an increased responsiveness to training. Here we used a mouse model of focal cortical stroke to test two hypotheses. First we investigated if responsiveness to training decreases over time after stroke. Second, we tested whether fluoxetine, which can influence synaptic plasticity and stroke recovery, can prolong the period over which large training-related gains can be elicited after stroke. Methods Mice were trained to perform a skilled prehension task to an asymptotic level of performance after which they underwent stroke induction in the caudal forelimb area (CFA). The mice were then retrained after a 1-day or 7-day delay with and without fluoxetine. Results Recovery of prehension after a CFA stroke was complete if training was initiated one day after stroke but incomplete if it was delayed by 7 days. In contrast, if fluoxetine was administered at 24 hours after stroke, then complete recovery of prehension was observed even with the 7-day training delay. Fluoxetine appeared to mediate its beneficial effect by reducing inhibitory interneuron expression in intact premotor cortex rather than through effects on infarct volume or cell death. Conclusions There is a gradient of diminishing responsiveness to motor training over the first week after stroke. Fluoxetine can overcome this gradient and maintain maximal levels of responsiveness to training even 7 days after stroke. PMID:26294676

Fluoxetine Maintains a State of Heightened Responsiveness to Motor Training Early After Stroke in a Mouse Model.

PubMed

Ng, Kwan L; Gibson, Ellen M; Hubbard, Robert; Yang, Juemin; Caffo, Brian; O'Brien, Richard J; Krakauer, John W; Zeiler, Steven R

2015-10-01

Data from both humans and animal models suggest that most recovery from motor impairment after stroke occurs in a sensitive period that lasts only weeks and is mediated, in part, by an increased responsiveness to training. Here, we used a mouse model of focal cortical stroke to test 2 hypotheses. First, we investigated whether responsiveness to training decreases over time after stroke. Second, we tested whether fluoxetine, which can influence synaptic plasticity and stroke recovery, can prolong the period over which large training-related gains can be elicited after stroke. Mice were trained to perform a skilled prehension task to an asymptotic level of performance after which they underwent stroke induction in the caudal forelimb area. The mice were then retrained after a 1- or 7-day delay with and without fluoxetine. Recovery of prehension after a caudal forelimb area stroke was complete if training was initiated 1 day after stroke but incomplete if it was delayed by 7 days. In contrast, if fluoxetine was administered at 24 hours after stroke, then complete recovery of prehension was observed even with the 7-day training delay. Fluoxetine seemed to mediate its beneficial effect by reducing inhibitory interneuron expression in intact premotor cortex rather than through effects on infarct volume or cell death. There is a gradient of diminishing responsiveness to motor training over the first week after stroke. Fluoxetine can overcome this gradient and maintain maximal levels of responsiveness to training even 7 days after stroke. © 2015 American Heart Association, Inc.

Inhibition of TRPC3 downregulates airway hyperresponsiveness, remodeling of OVA-sensitized mouse

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wang, Lingwei; Li, Jie; Integrated Chinese and Western Medicine Postdoctoral Research Station, Jinan University, Guangzhou

Airway hyperresponsiveness (AHR), airway remodeling and inflammation are the fundamental pathological alterations that occur in asthma. Transient receptor potential canonical 3 (TRPC3) has been implicated in diverse functions of airway smooth muscle cells (ASMCs) in asthma. However, the underlying mechanisms remain incompletely understood. We investigated the mRNA and protein expression of TRPC3 in ASMCs from normal and OVA-sensitized mouse. And the effects of inhibition or knockdown of TRPC3 with Ethyl-1- (4- (2,3,3-trichloroacrylamide) phenyl) −5 - (trifluoromethyl) -1H -pyrazole -4-carboxylate (Pyr3) and lentiviral shRNA on OVA-sensitized mouse AHR, airway remodeling, circulating inflammatory cytokines, cell proliferation and migration. We found that TRPC3 mRNAmore » and protein expression levels were significantly increased in ASMCs from OVA-sensitized mouse. Inhibiting TRPC3 with continuous subcutaneous administration of Pyr3 decreased enhanced pause (Penh) of OVA-sensitized mouse. Meanwhile, both Pyr3 and lentiviral shRNA treatment of ASMCs in OVA-sensitized mouse significantly decreased their proliferation and migration. These results suggest that TRPC3 plays a critical role in asthma and represents a promising new target for asthma treatment. - Highlights: • Penh, airway remodeling and the gene expression and protein of TRPC3 are increased in OVA-sensitized mice. • Inhibition of TRPC3 suppresses the OVA-sensitized mice Penh and airway remodeling. • Inhibition of TRPC3 decreases OVA-sensitized mice ASMC proliferation and migration.« less

Intracellular disposal of incompletely folded human alpha1-antitrypsin involves release from calnexin and post-translational trimming of asparagine-linked oligosaccharides.

PubMed

Liu, Y; Choudhury, P; Cabral, C M; Sifers, R N

1997-03-21

Protection of lung elastin fibers from proteolytic destruction is compromised by inefficient secretion of incompletely folded allelic variants of human alpha1-antitrypsin from hepatocytes. Pulse-chase radiolabeling with [35S]methionine and sucrose gradient sedimentation and coimmunoprecipitation techniques were employed to investigate quality control of human alpha1-antitrypsin secretion from stably transfected mouse hepatoma cells. The secretion-incompetent variant null(Hong Kong) (Sifers, R. N., Brashears-Macatee, S., Kidd, V. J., Muensch, H., and Woo, S. L. C. (1988) J. Biol. Chem. 263, 7330-7335) cannot fold into a functional conformation and was quantitatively associated with the molecular chaperone calnexin following biosynthesis. Assembly with calnexin required cotranslational trimming of glucose from asparagine-linked oligosaccharides. Intracellular disposal of pulse-radiolabeled molecules coincided with their release from calnexin. Released monomers and intracellular disposal were nonexistent in cells chased with cycloheximide, an inhibitor of protein synthesis. Post-translational trimming of asparagine-linked oligosaccharides and intracellular disposal were abrogated by 1-deoxymannojirimycin, an inhibitor of alpha-mannosidase activity, without affecting the monomer population. The data are consistent with a recently proposed quality control model (Hammond, C., Braakman, I., and Helenius, A. (1994) Proc. Natl. Acad. Sci. U. S. A. 91, 913-917) in which intracellular disposal requires dissociation from calnexin and post-translational trimming of mannose from asparagine-linked oligosaccharides.

IL-27 as a novel therapy for inflammatory bowel disease: a critical review of the literature

PubMed Central

Andrews, Caroline; McLean, Mairi H; Durum, Scott K

2016-01-01

Inflammatory bowel disease (IBD) is an inflammatory disorder of the intestine that affects an estimated 329 per 100,000 people in the United States and is increasing in incidence within a number of cultures worldwide. Likely due to its incompletely understood pathophysiology and etiology, standard treatments for IBD are only efficacious in subsets of patients and often do not induce lasting remission. As a result, novel therapies are needed. The success of anti-tumor necrosis factor-α treatment in a subset of IBD patients demonstrated that therapy targeting a single cytokine could be efficacious in IBD, and clinical trials investigating the blockade of a variety of cytokines have commenced. IL-27 is a relatively recently discovered type I cytokine with established roles in infectious disease, autoimmunity, and cancer in a variety of organs. IL-27 was identified as a candidate gene for IBD, and a number of studies in mouse models of IBD have demonstrated that IL-27 therapy is protective. However, in contrast to these investigations, genetic deletion of the IL-27 receptor has been shown to be protective in some mouse models of IBD. The purpose of this review is to highlight recent literature investigating the role of IL-27 in IBD, and to discuss possible explanations for the sometimes conflicting results of these studies. Evidence supporting IL-27 therapy as a treatment for IBD will also be discussed. PMID:27243591

Keratin 17 null mice exhibit age- and strain-dependent alopecia.

PubMed

McGowan, Kevin M; Tong, Xuemei; Colucci-Guyon, Emma; Langa, Francina; Babinet, Charles; Coulombe, Pierre A

2002-06-01

Onset of type I keratin 17 (K17) synthesis marks the adoption of an appendageal fate within embryonic ectoderm, and its expression persists in specific cell types within mature hair, glands, and nail. We report that K17 null mice develop severe alopecia during the first week postbirth, correlating with hair fragility, alterations in follicular histology, and apoptosis in matrix cells. These alterations are incompletely penetrant and normalize starting with the first postnatal cycle. Absence of a hair phenotype correlates with a genetic strain-dependent compensation by related keratins, including K16. These findings reveal a crucial role for K17 in the structural integrity of the first hair produced and the survival of hair-producing cells. Given that identical inherited mutations in this gene can cause either pachyonychia congenita or steatocystoma multiplex, the features of this mouse model suggest that this clinical heterogeneity arises from a cell type-specific, genetically determined compensation by related keratins.

Safety assessment for In-service Pressure Bending Pipe Containing Incomplete Penetration Defects

NASA Astrophysics Data System (ADS)

Wang, M.; Tang, P.; Xia, J. F.; Ling, Z. W.; Cai, G. Y.

2017-12-01

Incomplete penetration defect is a common defect in the welded joint of pressure pipes. While the safety classification of pressure pipe containing incomplete penetration defects, according to periodical inspection regulations in present, is more conservative. For reducing the repair of incomplete penetration defect, a scientific and applicable safety assessment method for pressure pipe is needed. In this paper, the stress analysis model of the pipe system was established for the in-service pressure bending pipe containing incomplete penetration defects. The local finite element model was set up to analyze the stress distribution of defect location and the stress linearization. And then, the applicability of two assessment methods, simplified assessment and U factor assessment method, to the assessment of incomplete penetration defects located at pressure bending pipe were analyzed. The results can provide some technical supports for the safety assessment of complex pipelines in the future.

Use of metaknowledge in the verification of knowledge-based systems

NASA Technical Reports Server (NTRS)

Morell, Larry J.

1989-01-01

Knowledge-based systems are modeled as deductive systems. The model indicates that the two primary areas of concern in verification are demonstrating consistency and completeness. A system is inconsistent if it asserts something that is not true of the modeled domain. A system is incomplete if it lacks deductive capability. Two forms of consistency are discussed along with appropriate verification methods. Three forms of incompleteness are discussed. The use of metaknowledge, knowledge about knowledge, is explored in connection to each form of incompleteness.

Influence of incomplete fusion on complete fusion at energies above the Coulomb barrier

NASA Astrophysics Data System (ADS)

Shuaib, Mohd; Sharma, Vijay R.; Yadav, Abhishek; Sharma, Manoj Kumar; Singh, Pushpendra P.; Singh, Devendra P.; Kumar, R.; Singh, R. P.; Muralithar, S.; Singh, B. P.; Prasad, R.

2017-10-01

In the present work, excitation functions of several reaction residues in the system 19F+169Tm, populated via the complete and incomplete fusion processes, have been measured using off-line γ-ray spectroscopy. The analysis of excitation functions has been done within the framework of statistical model code pace4. The excitation functions of residues populated via xn and pxn channels are found to be in good agreement with those estimated by the theoretical model code, which confirms the production of these residues solely via complete fusion process. However, a significant enhancement has been observed in the cross-sections of residues involving α-emitting channels as compared to the theoretical predictions. The observed enhancement in the cross-sections has been attributed to the incomplete fusion processes. In order to have a better insight into the onset and strength of incomplete fusion, the incomplete fusion strength function has been deduced. At present, there is no theoretical model available which can satisfactorily explain the incomplete fusion reaction data at energies ≈4-6 MeV/nucleon. In the present work, the influence of incomplete fusion on complete fusion in the 19F+169Tm system has also been studied. The measured cross-section data may be important for the development of reactor technology as well. It has been found that the incomplete fusion strength function strongly depends on the α-Q value of the projectile, which is found to be in good agreement with the existing literature data. The analysis strongly supports the projectile-dependent mass-asymmetry systematics. In order to study the influence of Coulomb effect ({Z}{{P}}{Z}{{T}}) on incomplete fusion, the deduced strength function for the present work is compared with the nearby projectile-target combinations. The incomplete fusion strength function is found to increase linearly with {Z}{{P}}{Z}{{T}}, indicating a strong influence of Coulomb effect in the incomplete fusion reactions.

Low Complexity Models to improve Incomplete Sensitivities for Shape Optimization

NASA Astrophysics Data System (ADS)

Stanciu, Mugurel; Mohammadi, Bijan; Moreau, Stéphane

2003-01-01

The present global platform for simulation and design of multi-model configurations treat shape optimization problems in aerodynamics. Flow solvers are coupled with optimization algorithms based on CAD-free and CAD-connected frameworks. Newton methods together with incomplete expressions of gradients are used. Such incomplete sensitivities are improved using reduced models based on physical assumptions. The validity and the application of this approach in real-life problems are presented. The numerical examples concern shape optimization for an airfoil, a business jet and a car engine cooling axial fan.

The molecular signature of impaired diabetic wound healing identifies serpinB3 as a healing biomarker.

PubMed

Fadini, Gian Paolo; Albiero, Mattia; Millioni, Renato; Poncina, Nicol; Rigato, Mauro; Scotton, Rachele; Boscari, Federico; Brocco, Enrico; Arrigoni, Giorgio; Villano, Gianmarco; Turato, Cristian; Biasiolo, Alessandra; Pontisso, Patrizia; Avogaro, Angelo

2014-09-01

Chronic foot ulceration is a severe complication of diabetes, driving morbidity and mortality. The mechanisms underlying delaying wound healing in diabetes are incompletely understood and tools to identify such pathways are eagerly awaited. Wound biopsies were obtained from 75 patients with diabetic foot ulcers. Matched subgroups of rapidly healing (RH, n = 17) and non-healing (NH, n = 11) patients were selected. Proteomic analysis was performed by labelling with isobaric tag for relative and absolute quantification and mass spectrometry. Differentially expressed proteins were analysed in NH vs RH for identification of pathogenic pathways. Individual sample gene/protein validation and in vivo validation of candidate pathways in mouse models were carried out. Pathway analyses were conducted on 92/286 proteins that were differentially expressed in NH vs RH. The following pathways were enriched in NH vs RH patients: apoptosis, protease inhibitors, epithelial differentiation, serine endopeptidase activity, coagulation and regulation of defence response. SerpinB3 was strongly upregulated in RH vs NH wounds, validated as protein and mRNA in individual samples. To test the relevance of serpinB3 in vivo, we used a transgenic mouse model with α1-antitrypsin promoter-driven overexpression of human SERPINB3. In this model, wound healing was unaffected by SERPINB3 overexpression in non-diabetic or diabetic mice with or without hindlimb ischaemia. In an independent validation cohort of 47 patients, high serpinB3 protein content was confirmed as a biomarker of healing improvement. We provide a benchmark for the unbiased discovery of novel molecular targets and biomarkers of impaired diabetic wound healing. High serpinB3 protein content was found to be a biomarker of successful healing in diabetic patients.

Nuclear lamina defects cause ATM-dependent NF-κB activation and link accelerated aging to a systemic inflammatory response

PubMed Central

Osorio, Fernando G.; Bárcena, Clea; Soria-Valles, Clara; Ramsay, Andrew J.; de Carlos, Félix; Cobo, Juan; Fueyo, Antonio; Freije, José M.P.; López-Otín, Carlos

2012-01-01

Alterations in the architecture and dynamics of the nuclear lamina have a causal role in normal and accelerated aging through both cell-autonomous and systemic mechanisms. However, the precise nature of the molecular cues involved in this process remains incompletely defined. Here we report that the accumulation of prelamin A isoforms at the nuclear lamina triggers an ATM- and NEMO-dependent signaling pathway that leads to NF-κB activation and secretion of high levels of proinflammatory cytokines in two different mouse models of accelerated aging (Zmpste24−/− and LmnaG609G/G609G mice). Causal involvement of NF-κB in accelerated aging was demonstrated by the fact that both genetic and pharmacological inhibition of NF-κB signaling prevents age-associated features in these animal models, significantly extending their longevity. Our findings provide in vivo proof of principle for the feasibility of pharmacological modulation of the NF-κB pathway to slow down the progression of physiological and pathological aging. PMID:23019125

No Effect of Dietary Aspartame or Stevia on Pancreatic Acinar Carcinoma Development, Growth, or Induced Mortality in a Murine Model

PubMed Central

Dooley, James; Lagou, Vasiliki; Dresselaers, Tom; van Dongen, Katinka A.; Himmelreich, Uwe; Liston, Adrian

2017-01-01

Pancreatic cancer has an extremely poor prognosis, largely due to a poor record for early detection. Known risk factors for pancreatic cancer include obesity, diet, and diabetes, implicating glucose consumption and regulation as a key player. The role of artificial sweeteners may therefore be pertinent to disease kinetics. The oncogenic impact of artificial sweeteners is a highly controversial area. Aspartame, one of the most studied food additives, is widely recognized as being generally safe, although there are still specific areas where research is incomplete due to study limitations. Stevia, by contrast, has been the subject of relatively few studies, and the potential health benefits are based on extrapolation rather than direct testing. Here, we used longitudinal tracking of pancreatic acinar carcinoma development, growth, and lethality in a sensitized mouse model. Despite exposure to aspartame and stevia from the in utero stage onward, we found no disease modification activity, in either direction. These results contribute to the data on aspartame and stevia safety, while also reducing confidence in several of the purported health benefits. PMID:28232906

GSDMD is critical for autoinflammatory pathology in a mouse model of Familial Mediterranean Fever.

PubMed

Kanneganti, Apurva; Malireddi, R K Subbarao; Saavedra, Pedro H V; Vande Walle, Lieselotte; Van Gorp, Hanne; Kambara, Hiroto; Tillman, Heather; Vogel, Peter; Luo, Hongbo R; Xavier, Ramnik J; Chi, Hongbo; Lamkanfi, Mohamed

2018-06-04

Pyroptosis is an inflammasome-induced lytic cell death mode, the physiological role of which in chronic inflammatory diseases is unknown. Familial Mediterranean Fever (FMF) is the most common monogenic autoinflammatory disease worldwide, affecting an estimated 150,000 patients. The disease is caused by missense mutations in Mefv that activate the Pyrin inflammasome, but the pathophysiologic mechanisms driving autoinflammation in FMF are incompletely understood. Here, we show that Clostridium difficile infection of FMF knock-in macrophages that express a chimeric FMF-associated Mefv V726A Pyrin elicited pyroptosis and gasdermin D (GSDMD)-mediated interleukin (IL)-1β secretion. Importantly, in vivo GSDMD deletion abolished spontaneous autoinflammatory disease. GSDMD-deficient FMF knock-in mice were fully protected from the runted growth, anemia, systemic inflammatory cytokine production, neutrophilia, and tissue damage that characterize this autoinflammatory disease model. Overall, this work identifies pyroptosis as a critical mechanism of IL-1β-dependent autoinflammation in FMF and highlights GSDMD inhibition as a potential antiinflammatory strategy in inflammasome-driven diseases. © 2018 Kanneganti et al.

Neurotensin increases mortality and mast cells reduce neurotensin levels in a mouse model of sepsis

PubMed Central

Piliponsky, Adrian M.; Chen, Ching-Cheng; Nishimura, Toshihiko; Metz, Martin; Rios, Eon J.; Dobner, Paul R.; Wada, Etsuko; Wada, Keiji; Zacharias, Sherma; Mohanasundaram, Uma; Faix, James D.; Abrink, Magnus; Pejler, Gunnar; Pearl, Ronald; Tsai, Mindy; Galli, Stephen J.

2010-01-01

Sepsis is a complex, incompletely understood and often fatal disorder,1 typically accompanied by hypotension,2 that is considered to represent a dysregulated host response to infection.3,4,5 Neurotensin (NT) is a 13-amino-acid peptide that, among its multiple effects, induces hypotension.6 We find that intraperitoneal and plasma concentrations of NT are increased in mice after severe caecal ligation and puncture (CLP), a model of sepsis, and that mice treated with a pharmacological antagonist of NT, or NT-deficient mice, exhibit reduced mortality during severe CLP. In mice, mast cells can degrade NT and reduce NT-induced hypotension and CLP-associated mortality, and optimal expression of these effects requires mast cell expression of neurotensin receptor 1 and neurolysin. These findings show that NT contributes to sepsis-related mortality in mice during severe CLP and that mast cells can lower NT concentrations, and suggest that mast cell-dependent reduction in NT levels contributes to the ability of mast cells to enhance survival after CLP. PMID:18376408

NegGOA: negative GO annotations selection using ontology structure.

PubMed

Fu, Guangyuan; Wang, Jun; Yang, Bo; Yu, Guoxian

2016-10-01

Predicting the biological functions of proteins is one of the key challenges in the post-genomic era. Computational models have demonstrated the utility of applying machine learning methods to predict protein function. Most prediction methods explicitly require a set of negative examples-proteins that are known not carrying out a particular function. However, Gene Ontology (GO) almost always only provides the knowledge that proteins carry out a particular function, and functional annotations of proteins are incomplete. GO structurally organizes more than tens of thousands GO terms and a protein is annotated with several (or dozens) of these terms. For these reasons, the negative examples of a protein can greatly help distinguishing true positive examples of the protein from such a large candidate GO space. In this paper, we present a novel approach (called NegGOA) to select negative examples. Specifically, NegGOA takes advantage of the ontology structure, available annotations and potentiality of additional annotations of a protein to choose negative examples of the protein. We compare NegGOA with other negative examples selection algorithms and find that NegGOA produces much fewer false negatives than them. We incorporate the selected negative examples into an efficient function prediction model to predict the functions of proteins in Yeast, Human, Mouse and Fly. NegGOA also demonstrates improved accuracy than these comparing algorithms across various evaluation metrics. In addition, NegGOA is less suffered from incomplete annotations of proteins than these comparing methods. The Matlab and R codes are available at https://sites.google.com/site/guoxian85/neggoa gxyu@swu.edu.cn Supplementary data are available at Bioinformatics online. © The Author 2016. Published by Oxford University Press. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

High-throughput discovery of novel developmental phenotypes.

PubMed

Dickinson, Mary E; Flenniken, Ann M; Ji, Xiao; Teboul, Lydia; Wong, Michael D; White, Jacqueline K; Meehan, Terrence F; Weninger, Wolfgang J; Westerberg, Henrik; Adissu, Hibret; Baker, Candice N; Bower, Lynette; Brown, James M; Caddle, L Brianna; Chiani, Francesco; Clary, Dave; Cleak, James; Daly, Mark J; Denegre, James M; Doe, Brendan; Dolan, Mary E; Edie, Sarah M; Fuchs, Helmut; Gailus-Durner, Valerie; Galli, Antonella; Gambadoro, Alessia; Gallegos, Juan; Guo, Shiying; Horner, Neil R; Hsu, Chih-Wei; Johnson, Sara J; Kalaga, Sowmya; Keith, Lance C; Lanoue, Louise; Lawson, Thomas N; Lek, Monkol; Mark, Manuel; Marschall, Susan; Mason, Jeremy; McElwee, Melissa L; Newbigging, Susan; Nutter, Lauryl M J; Peterson, Kevin A; Ramirez-Solis, Ramiro; Rowland, Douglas J; Ryder, Edward; Samocha, Kaitlin E; Seavitt, John R; Selloum, Mohammed; Szoke-Kovacs, Zsombor; Tamura, Masaru; Trainor, Amanda G; Tudose, Ilinca; Wakana, Shigeharu; Warren, Jonathan; Wendling, Olivia; West, David B; Wong, Leeyean; Yoshiki, Atsushi; MacArthur, Daniel G; Tocchini-Valentini, Glauco P; Gao, Xiang; Flicek, Paul; Bradley, Allan; Skarnes, William C; Justice, Monica J; Parkinson, Helen E; Moore, Mark; Wells, Sara; Braun, Robert E; Svenson, Karen L; de Angelis, Martin Hrabe; Herault, Yann; Mohun, Tim; Mallon, Ann-Marie; Henkelman, R Mark; Brown, Steve D M; Adams, David J; Lloyd, K C Kent; McKerlie, Colin; Beaudet, Arthur L; Bućan, Maja; Murray, Stephen A

2016-09-22

Approximately one-third of all mammalian genes are essential for life. Phenotypes resulting from knockouts of these genes in mice have provided tremendous insight into gene function and congenital disorders. As part of the International Mouse Phenotyping Consortium effort to generate and phenotypically characterize 5,000 knockout mouse lines, here we identify 410 lethal genes during the production of the first 1,751 unique gene knockouts. Using a standardized phenotyping platform that incorporates high-resolution 3D imaging, we identify phenotypes at multiple time points for previously uncharacterized genes and additional phenotypes for genes with previously reported mutant phenotypes. Unexpectedly, our analysis reveals that incomplete penetrance and variable expressivity are common even on a defined genetic background. In addition, we show that human disease genes are enriched for essential genes, thus providing a dataset that facilitates the prioritization and validation of mutations identified in clinical sequencing efforts.

Composite Linear Models | Division of Cancer Prevention

Cancer.gov

By Stuart G. Baker The composite linear models software is a matrix approach to compute maximum likelihood estimates and asymptotic standard errors for models for incomplete multinomial data. It implements the method described in Baker SG. Composite linear models for incomplete multinomial data. Statistics in Medicine 1994;13:609-622. The software includes a library of thirty

Repair of exogenous DNA double-strand breaks promotes chromosome synapsis in SPO11-mutant mouse meiocytes, and is altered in the absence of HORMAD1.

PubMed

Carofiglio, Fabrizia; Sleddens-Linkels, Esther; Wassenaar, Evelyne; Inagaki, Akiko; van Cappellen, Wiggert A; Grootegoed, J Anton; Toth, Attila; Baarends, Willy M

2018-03-01

Repair of SPO11-dependent DNA double-strand breaks (DSBs) via homologous recombination (HR) is essential for stable homologous chromosome pairing and synapsis during meiotic prophase. Here, we induced radiation-induced DSBs to study meiotic recombination and homologous chromosome pairing in mouse meiocytes in the absence of SPO11 activity (Spo11 YF/YF model), and in the absence of both SPO11 and HORMAD1 (Spo11/Hormad1 dko). Within 30 min after 5 Gy irradiation of Spo11 YF/YF mice, 140-160 DSB repair foci were detected, which specifically localized to the synaptonemal complex axes. Repair of radiation-induced DSBs was incomplete in Spo11 YF/YF compared to Spo11 +/YF meiocytes. Still, repair of exogenous DSBs promoted partial recovery of chromosome pairing and synapsis in Spo11 YF/YF meiocytes. This indicates that at least part of the exogenous DSBs can be processed in an interhomolog recombination repair pathway. Interestingly, in a seperate experiment, using 3 Gy of irradiation, we observed that Spo11/Hormad1 dko spermatocytes contained fewer remaining DSB repair foci at 48 h after irradiation compared to irradiated Spo11 knockout spermatocytes. Together, these results show that recruitment of exogenous DSBs to the synaptonemal complex, in conjunction with repair of exogenous DSBs via the homologous chromosome, contributes to homology recognition. In addition, the data suggest a role for HORMAD1 in DNA repair pathway choice in mouse meiocytes. Copyright © 2018 The Authors. Published by Elsevier B.V. All rights reserved.

Species-specific disruption of STING-dependent antiviral cellular defenses by the Zika virus NS2B3 protease.

PubMed

Ding, Qiang; Gaska, Jenna M; Douam, Florian; Wei, Lei; Kim, David; Balev, Metodi; Heller, Brigitte; Ploss, Alexander

2018-06-18

The limited host tropism of numerous viruses causing disease in humans remains incompletely understood. One example is Zika virus (ZIKV), an RNA virus that has reemerged in recent years. Here, we demonstrate that ZIKV efficiently infects fibroblasts from humans, great apes, New and Old World monkeys, but not rodents. ZIKV infection in human-but not murine-cells impairs responses to agonists of the cGMP-AMP synthase/stimulator of IFN genes (cGAS/STING) signaling pathway, suggesting that viral mechanisms to evade antiviral defenses are less effective in rodent cells. Indeed, human, but not mouse, STING is subject to cleavage by proteases encoded by ZIKV, dengue virus, West Nile virus, and Japanese encephalitis virus, but not that of yellow fever virus. The protease cleavage site, located between positions 78/79 of human STING, is only partially conserved in nonhuman primates and rodents, rendering these orthologs resistant to degradation. Genetic disruption of STING increases the susceptibility of mouse-but not human-cells to ZIKV. Accordingly, expression of only mouse, not human, STING in murine STING knockout cells rescues the ZIKV suppression phenotype. STING-deficient mice, however, did not exhibit increased susceptibility, suggesting that other redundant antiviral pathways control ZIKV infection in vivo. Collectively, our data demonstrate that numerous RNA viruses evade cGAS/STING-dependent signaling and affirm the importance of this pathway in shaping the host range of ZIKV. Furthermore, our results explain-at least in part-the decreased permissivity of rodent cells to ZIKV, which could aid in the development of mice model with inheritable susceptibility to ZIKV and other flaviviruses.

Retinal lesions induce fast intrinsic cortical plasticity in adult mouse visual system.

PubMed

Smolders, Katrien; Vreysen, Samme; Laramée, Marie-Eve; Cuyvers, Annemie; Hu, Tjing-Tjing; Van Brussel, Leen; Eysel, Ulf T; Nys, Julie; Arckens, Lutgarde

2016-09-01

Neuronal activity plays an important role in the development and structural-functional maintenance of the brain as well as in its life-long plastic response to changes in sensory stimulation. We characterized the impact of unilateral 15° laser lesions in the temporal lower visual field of the retina, on visually driven neuronal activity in the afferent visual pathway of adult mice using in situ hybridization for the activity reporter gene zif268. In the first days post-lesion, we detected a discrete zone of reduced zif268 expression in the contralateral hemisphere, spanning the border between the monocular segment of the primary visual cortex (V1) with extrastriate visual area V2M. We could not detect a clear lesion projection zone (LPZ) in areas lateral to V1 whereas medial to V2M, agranular and granular retrosplenial cortex showed decreased zif268 levels over their full extent. All affected areas displayed a return to normal zif268 levels, and this was faster in higher order visual areas than in V1. The lesion did, however, induce a permanent LPZ in the retinorecipient layers of the superior colliculus. We identified a retinotopy-based intrinsic capacity of adult mouse visual cortex to recover from restricted vision loss, with recovery speed reflecting the areal cortical magnification factor. Our observations predict incomplete visual field representations for areas lateral to V1 vs. lack of retinotopic organization for areas medial to V2M. The validation of this mouse model paves the way for future interrogations of cortical region- and cell-type-specific contributions to functional recovery, up to microcircuit level. © 2015 Federation of European Neuroscience Societies and John Wiley & Sons Ltd.

Functional Targets of the Monogenic Diabetes Transcription Factors HNF-1α and HNF-4α Are Highly Conserved Between Mice and Humans

PubMed Central

Boj, Sylvia F.; Servitja, Joan Marc; Martin, David; Rios, Martin; Talianidis, Iannis; Guigo, Roderic; Ferrer, Jorge

2009-01-01

OBJECTIVE The evolutionary conservation of transcriptional mechanisms has been widely exploited to understand human biology and disease. Recent findings, however, unexpectedly showed that the transcriptional regulators hepatocyte nuclear factor (HNF)-1α and -4α rarely bind to the same genes in mice and humans, leading to the proposal that tissue-specific transcriptional regulation has undergone extensive divergence in the two species. Such observations have major implications for the use of mouse models to understand HNF-1α– and HNF-4α–deficient diabetes. However, the significance of studies that assess binding without considering regulatory function is poorly understood. RESEARCH DESIGN AND METHODS We compared previously reported mouse and human HNF-1α and HNF-4α binding studies with independent binding experiments. We also integrated binding studies with mouse and human loss-of-function gene expression datasets. RESULTS First, we confirmed the existence of species-specific HNF-1α and -4α binding, yet observed incomplete detection of binding in the different datasets, causing an underestimation of binding conservation. Second, only a minor fraction of HNF-1α– and HNF-4α–bound genes were downregulated in the absence of these regulators. This subset of functional targets did not show evidence for evolutionary divergence of binding or binding sequence motifs. Finally, we observed differences between conserved and species-specific binding properties. For example, conserved binding was more frequently located near transcriptional start sites and was more likely to involve multiple binding events in the same gene. CONCLUSIONS Despite evolutionary changes in binding, essential direct transcriptional functions of HNF-1α and -4α are largely conserved between mice and humans. PMID:19188435

Benefits and limitations of animal models in partial bladder outlet obstruction for translational research.

PubMed

Kitta, Takeya; Kanno, Yukiko; Chiba, Hiroki; Higuchi, Madoka; Ouchi, Mifuka; Togo, Mio; Moriya, Kimihiko; Shinohara, Nobuo

2018-01-01

The functions of the lower urinary tract have been investigated for more than a century. Lower urinary tract symptoms, such as incomplete bladder emptying, weak urine stream, daytime urinary frequency, urgency, urge incontinence and nocturia after partial bladder outlet obstruction, is a frequent cause of benign prostatic hyperplasia in aging men. However, the pathophysiological mechanisms have not been fully elucidated. The use of animal models is absolutely imperative for understanding the pathophysiological processes involved in bladder dysfunction. Surgical induction has been used to study lower urinary tract functions of numerous animal species, such as pig, dog, rabbit, guinea pig, rat and mouse, of both sexes. Several morphological and functional modifications under partial bladder outlet obstruction have not only been observed in the bladder, but also in the central nervous system. Understanding the changes of the lower urinary tract functions induced by partial bladder outlet obstruction would also contribute to appropriate drug development for treating these pathophysiological conditions. In the present review, we discuss techniques for creating partial bladder outlet obstruction, the characteristics of several species, as well as issues of each model, and their translational value. © 2017 The Japanese Urological Association.

Bone marrow endothelial progenitors augment atherosclerotic plaque regression in a mouse model of plasma lipid lowering

PubMed Central

Yao, Longbiao; Heuser-Baker, Janet; Herlea-Pana, Oana; Iida, Ryuji; Wang, Qilong; Zou, Ming-Hui; Barlic-Dicen, Jana

2012-01-01

The major event initiating atherosclerosis is hypercholesterolemia-induced disruption of vascular endothelium integrity. In settings of endothelial damage, endothelial progenitor cells (EPCs) are mobilized from bone marrow into circulation and home to sites of vascular injury where they aid endothelial regeneration. Given the beneficial effects of EPCs in vascular repair, we hypothesized that these cells play a pivotal role in atherosclerosis regression. We tested our hypothesis in the atherosclerosis-prone mouse model in which hypercholesterolemia, one of the main factors affecting EPC homeostasis, is reversible (Reversa mice). In these mice normalization of plasma lipids decreased atherosclerotic burden; however, plaque regression was incomplete. To explore whether endothelial progenitors contribute to atherosclerosis regression, bone marrow EPCs from a transgenic strain expressing green fluorescent protein under the control of endothelial cell-specific Tie2 promoter (Tie2-GFP+) were isolated. These cells were then adoptively transferred into atheroregressing Reversa recipients where they augmented plaque regression induced by reversal of hypercholesterolemia. Advanced plaque regression correlated with engraftment of Tie2-GFP+ EPCs into endothelium and resulted in an increase in atheroprotective nitric oxide and improved vascular relaxation. Similarly augmented plaque regression was also detected in regressing Reversa mice treated with the stem cell mobilizer AMD3100 which also mobilizes EPCs to peripheral blood. We conclude that correction of hypercholesterolemia in Reversa mice leads to partial plaque regression that can be augmented by AMD3100 treatment or by adoptive transfer of EPCs. This suggests that direct cell therapy or indirect progenitor cell mobilization therapy may be used in combination with statins to treat atherosclerosis. PMID:23081735

Differentiation of C2C12 myoblasts expressing lamin A mutated at a site responsible for Emery-Dreifuss muscular dystrophy is improved by inhibition of the MEK-ERK pathway and stimulation of the PI3-kinase pathway

DOE Office of Scientific and Technical Information (OSTI.GOV)

Favreau, Catherine; Delbarre, Erwan; Courvalin, Jean-Claude

2008-04-01

Mutation R453W in A-type lamins, that are major nuclear envelope proteins, generates Emery-Dreifuss muscular dystrophy. We previously showed that mouse myoblasts expressing R453W-lamin A incompletely exit the cell cycle and differentiate into myocytes with a low level of multinucleation. Here we attempted to improve differentiation by treating these cells with a mixture of PD98059, an extracellular-regulated kinase (ERK) kinase (also known as mitogen-activated kinase, MEK) inhibitor, and insulin-like growth factor-II, an activator of phosphoinositide 3-kinase. We show that mouse myoblasts expressing R453W-lamin A were sensitive to the drug treatment as shown by (i) an increase in multinucleation, (ii) downregulation ofmore » proliferation markers (cyclin D1, hyperphosphorylated Rb), (iii) upregulation of myogenin, and (iv) sustained activation of p21 and cyclin D3. However, nuclear matrix anchorage of p21 and cyclin D3 in a complex with hypophosphorylated Rb that is critical to trigger cell cycle arrest and myogenin induction was deficient and incompletely restored by drug treatment. As the turn-over of R453W-lamin A at the nuclear envelope was greatly enhanced, we propose that R453W-lamin A impairs the capacity of the nuclear lamina to serve as scaffold for substrates of the MEK-ERK pathway and for MyoD-induced proteins that play a role in the differentiation process.« less

Acylcarnitines: potential implications for skeletal muscle insulin resistance.

PubMed

Aguer, Céline; McCoin, Colin S; Knotts, Trina A; Thrush, A Brianne; Ono-Moore, Kikumi; McPherson, Ruth; Dent, Robert; Hwang, Daniel H; Adams, Sean H; Harper, Mary-Ellen

2015-01-01

Insulin resistance may be linked to incomplete fatty acid β-oxidation and the subsequent increase in acylcarnitine species in different tissues including skeletal muscle. It is not known if acylcarnitines participate in muscle insulin resistance or simply reflect dysregulated metabolism. The aims of this study were to determine whether acylcarnitines can elicit muscle insulin resistance and to better understand the link between incomplete muscle fatty acid β-oxidation, oxidative stress, inflammation, and insulin-resistance development. Differentiated C2C12, primary mouse, and human myotubes were treated with acylcarnitines (C4:0, C14:0, C16:0) or with palmitate with or without carnitine acyltransferase inhibition by mildronate. Treatment with C4:0, C14:0, and C16:0 acylcarnitines resulted in 20-30% decrease in insulin response at the level of Akt phosphorylation and/or glucose uptake. Mildronate reversed palmitate-induced insulin resistance concomitant with an ∼25% decrease in short-chain acylcarnitine and acetylcarnitine secretion. Although proinflammatory cytokines were not affected under these conditions, oxidative stress was increased by 2-3 times by short- or long-chain acylcarnitines. Acylcarnitine-induced oxidative stress and insulin resistance were reversed by treatment with antioxidants. Results are consistent with the conclusion that incomplete muscle fatty acid β-oxidation causes acylcarnitine accumulation and associated oxidative stress, raising the possibility that these metabolites play a role in muscle insulin resistance. © FASEB.

Compensatory axon sprouting for very slow axonal die-back in a transgenic model of spinal muscular atrophy type III.

PubMed

Udina, Esther; Putman, Charles T; Harris, Luke R; Tyreman, Neil; Cook, Victoria E; Gordon, Tessa

2017-03-01

Smn +/- transgenic mouse is a model of the mildest form of spinal muscular atrophy. Although there is a loss of spinal motoneurons in 11-month-old animals, muscular force is maintained. This maintained muscular force is mediated by reinnervation of the denervated fibres by surviving motoneurons. The spinal motoneurons in these animals do not show an increased susceptibility to death after nerve injury and they retain their regenerative capacity. We conclude that the hypothesized immaturity of the neuromuscular system in this model cannot explain the loss of motoneurons by systematic die-back. Spinal muscular atrophy (SMA) is a common autosomal recessive disorder in humans and is the leading genetic cause of infantile death. Patients lack the SMN1 gene with the severity of the disease depending on the number of copies of the highly homologous SMN2 gene. Although motoneuron death in the Smn +/- transgenic mouse model of the mildest form of SMA, SMA type III, has been reported, we have used retrograde tracing of sciatic and femoral motoneurons in the hindlimb with recording of muscle and motor unit isometric forces to count the number of motoneurons with intact neuromuscular connections. Thereby, we investigated whether incomplete maturation of the neuromuscular system induced by survival motoneuron protein (SMN) defects is responsible for die-back of axons relative to survival of motoneurons. First, a reduction of ∼30% of backlabelled motoneurons began relatively late, at 11 months of age, with a significant loss of 19% at 7 months. Motor axon die-back was affirmed by motor unit number estimation. Loss of functional motor units was fully compensated by axonal sprouting to retain normal contractile force in four hindlimb muscles (three fast-twitch and one slow-twitch) innervated by branches of the sciatic nerve. Second, our evaluation of whether axotomy of motoneurons in the adult Smn +/- transgenic mouse increases their susceptibility to cell death demonstrated that all the motoneurons survived and they sustained their capacity to regenerate their nerve fibres. It is concluded the systematic die-back of motoneurons that innervate both fast- and slow-twitch muscle fibres is not related to immaturity of the neuromuscular system in SMA. © 2016 The Authors. The Journal of Physiology © 2016 The Physiological Society.

Xiao-Qing-Long-Tang shows preventive effect of asthma in an allergic asthma mouse model through neurotrophin regulation

PubMed Central

2013-01-01

Background This study investigates the effect of Xiao-Qing-Long-Tang (XQLT) on neurotrophin in an established mouse model of Dermatophagoides pteronyssinus (Der p)-induced acute allergic asthma and in a LA4 cell line model of lung adenoma. The effects of XQLT on the regulation of nerve growth factor (NGF) and brain-derived neurotrophic factor (BDNF), airway hyper-responsiveness (AHR) and immunoglobulin E were measured. Methods LA4 cells were stimulated with 100 μg/ml Der p 24 h and the supernatant was collected for ELISA analysis. Der p-stimulated LA4 cells with either XQLT pre-treatment or XQLT co-treatment were used to evaluate the XQLT effect on neurotrophin. Balb/c mice were sensitized on days 0 and 7 with a base-tail injection of 50 μg Dermatophagoides pteronyssinus (Der p) that was emulsified in 50 μl incomplete Freund’s adjuvant (IFA). On day 14, mice received an intra-tracheal challenge of 50 μl Der p (2 mg/ml). XQLT (1g/Kg) was administered orally to mice either on days 2, 4, 6, 8, 10 and 12 as a preventive strategy or on day 15 as a therapeutic strategy. Results XQLT inhibited expression of those NGF, BDNF and thymus-and activation-regulated cytokine (TARC) in LA4 cells that were subjected to a Der p allergen. Both preventive and therapeutic treatments with XQLT in mice reduced AHR. Preventive treatment with XQLT markedly decreased NGF in broncho-alveolar lavage fluids (BALF) and BDNF in serum, whereas therapeutic treatment reduced only serum BDNF level. The reduced NGF levels corresponded to a decrease in AHR by XQLT treatment. Reduced BALF NGF and TARC and serum BDNF levels may have been responsible for decreased eosinophil infiltration into lung tissue. Immunohistochemistry showed that p75NTR and TrkA levels were reduced in the lungs of mice under both XQLT treatment protocols, and this reduction may have been correlated with the prevention of the asthmatic reaction by XQLT. Conclusion XQLT alleviated allergic inflammation including AHR, IgE elevation and eosinophil infiltration in Der p stimulated mice by regulating neurotrophin and reducing TARC. These results revealed the potential pharmacological targets on which the XQLT decotion exerts preventive and therapeutic effects in an allergic asthma mouse model. PMID:24010817

In situ proliferation contributes to accumulation of tumor-associated macrophages in spontaneous mammary tumors.

PubMed

Tymoszuk, Piotr; Evens, Hanneke; Marzola, Vanessa; Wachowicz, Katarzyna; Wasmer, Marie-Helene; Datta, Sebak; Müller-Holzner, Elisabeth; Fiegl, Heidi; Böck, Günther; van Rooijen, Nico; Theurl, Igor; Doppler, Wolfgang

2014-08-01

Infiltration of a neoplasm with tumor-associated macrophages (TAMs) is considered an important negative prognostic factor and is functionally associated with tumor vascularization, accelerated growth, and dissemination. However, the ontogeny and differentiation pathways of TAMs are only incompletely characterized. Here, we report that intense local proliferation of fully differentiated macrophages rather than low-pace recruitment of blood-borne precursors drives TAM accumulation in a mouse model of spontaneous mammary carcinogenesis, the MMTVneu strain. TAM differentiation and expansion is regulated by CSF1, whose expression is directly controlled by STAT1 at the gene promoter level. These findings appear to be also relevant for human breast cancer, in which an interrelationship between STAT1, CSF1, and macrophage marker expression was identified. We propose that, akin to various MU subtypes in nonmalignant tissues, local proliferation and CSF1 play a vital role in the homeostasis of TAMs. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

A High-Dimensional Atlas of Human T Cell Diversity Reveals Tissue-Specific Trafficking and Cytokine Signatures.

PubMed

Wong, Michael Thomas; Ong, David Eng Hui; Lim, Frances Sheau Huei; Teng, Karen Wei Weng; McGovern, Naomi; Narayanan, Sriram; Ho, Wen Qi; Cerny, Daniela; Tan, Henry Kun Kiaang; Anicete, Rosslyn; Tan, Bien Keem; Lim, Tony Kiat Hon; Chan, Chung Yip; Cheow, Peng Chung; Lee, Ser Yee; Takano, Angela; Tan, Eng-Huat; Tam, John Kit Chung; Tan, Ern Yu; Chan, Jerry Kok Yen; Fink, Katja; Bertoletti, Antonio; Ginhoux, Florent; Curotto de Lafaille, Maria Alicia; Newell, Evan William

2016-08-16

Depending on the tissue microenvironment, T cells can differentiate into highly diverse subsets expressing unique trafficking receptors and cytokines. Studies of human lymphocytes have primarily focused on a limited number of parameters in blood, representing an incomplete view of the human immune system. Here, we have utilized mass cytometry to simultaneously analyze T cell trafficking and functional markers across eight different human tissues, including blood, lymphoid, and non-lymphoid tissues. These data have revealed that combinatorial expression of trafficking receptors and cytokines better defines tissue specificity. Notably, we identified numerous T helper cell subsets with overlapping cytokine expression, but only specific cytokine combinations are secreted regardless of tissue type. This indicates that T cell lineages defined in mouse models cannot be clearly distinguished in humans. Overall, our data uncover a plethora of tissue immune signatures and provide a systemic map of how T cell phenotypes are altered throughout the human body. Copyright © 2016 Elsevier Inc. All rights reserved.

Pathogenic Fungi Regulate Immunity by Inducing Neutrophilic Myeloid-Derived Suppressor Cells

PubMed Central

Rieber, Nikolaus; Singh, Anurag; Öz, Hasan; Carevic, Melanie; Bouzani, Maria; Amich, Jorge; Ost, Michael; Ye, Zhiyong; Ballbach, Marlene; Schäfer, Iris; Mezger, Markus; Klimosch, Sascha N.; Weber, Alexander N.R.; Handgretinger, Rupert; Krappmann, Sven; Liese, Johannes; Engeholm, Maik; Schüle, Rebecca; Salih, Helmut Rainer; Marodi, Laszlo; Speckmann, Carsten; Grimbacher, Bodo; Ruland, Jürgen; Brown, Gordon D.; Beilhack, Andreas; Loeffler, Juergen; Hartl, Dominik

2015-01-01

Summary Despite continuous contact with fungi, immunocompetent individuals rarely develop pro-inflammatory antifungal immune responses. The underlying tolerogenic mechanisms are incompletely understood. Using both mouse models and human patients, we show that infection with the human pathogenic fungi Aspergillus fumigatus and Candida albicans induces a distinct subset of neutrophilic myeloid-derived suppressor cells (MDSCs), which functionally suppress T and NK cell responses. Mechanistically, pathogenic fungi induce neutrophilic MDSCs through the pattern recognition receptor Dectin-1 and its downstream adaptor protein CARD9. Fungal MDSC induction is further dependent on pathways downstream of Dectin-1 signaling, notably reactive oxygen species (ROS) generation as well as caspase-8 activity and interleukin-1 (IL-1) production. Additionally, exogenous IL-1β induces MDSCs to comparable levels observed during C. albicans infection. Adoptive transfer and survival experiments show that MDSCs are protective during invasive C. albicans infection, but not A. fumigatus infection. These studies define an innate immune mechanism by which pathogenic fungi regulate host defense. PMID:25771792

Keratin 17 null mice exhibit age- and strain-dependent alopecia

PubMed Central

McGowan, Kevin M.; Tong, Xuemei; Colucci-Guyon, Emma; Langa, Francina; Babinet, Charles; Coulombe, Pierre A.

2002-01-01

Onset of type I keratin 17 (K17) synthesis marks the adoption of an appendageal fate within embryonic ectoderm, and its expression persists in specific cell types within mature hair, glands, and nail. We report that K17 null mice develop severe alopecia during the first week postbirth, correlating with hair fragility, alterations in follicular histology, and apoptosis in matrix cells. These alterations are incompletely penetrant and normalize starting with the first postnatal cycle. Absence of a hair phenotype correlates with a genetic strain-dependent compensation by related keratins, including K16. These findings reveal a crucial role for K17 in the structural integrity of the first hair produced and the survival of hair-producing cells. Given that identical inherited mutations in this gene can cause either pachyonychia congenita or steatocystoma multiplex, the features of this mouse model suggest that this clinical heterogeneity arises from a cell type-specific, genetically determined compensation by related keratins. PMID:12050118

A statistical approach to identify, monitor, and manage incomplete curated data sets.

PubMed

Howe, Douglas G

2018-04-02

Many biological knowledge bases gather data through expert curation of published literature. High data volume, selective partial curation, delays in access, and publication of data prior to the ability to curate it can result in incomplete curation of published data. Knowing which data sets are incomplete and how incomplete they are remains a challenge. Awareness that a data set may be incomplete is important for proper interpretation, to avoiding flawed hypothesis generation, and can justify further exploration of published literature for additional relevant data. Computational methods to assess data set completeness are needed. One such method is presented here. In this work, a multivariate linear regression model was used to identify genes in the Zebrafish Information Network (ZFIN) Database having incomplete curated gene expression data sets. Starting with 36,655 gene records from ZFIN, data aggregation, cleansing, and filtering reduced the set to 9870 gene records suitable for training and testing the model to predict the number of expression experiments per gene. Feature engineering and selection identified the following predictive variables: the number of journal publications; the number of journal publications already attributed for gene expression annotation; the percent of journal publications already attributed for expression data; the gene symbol; and the number of transgenic constructs associated with each gene. Twenty-five percent of the gene records (2483 genes) were used to train the model. The remaining 7387 genes were used to test the model. One hundred and twenty-two and 165 of the 7387 tested genes were identified as missing expression annotations based on their residuals being outside the model lower or upper 95% confidence interval respectively. The model had precision of 0.97 and recall of 0.71 at the negative 95% confidence interval and precision of 0.76 and recall of 0.73 at the positive 95% confidence interval. This method can be used to identify data sets that are incompletely curated, as demonstrated using the gene expression data set from ZFIN. This information can help both database resources and data consumers gauge when it may be useful to look further for published data to augment the existing expertly curated information.

Impact of observational incompleteness on the structural properties of protein interaction networks

NASA Astrophysics Data System (ADS)

Kuhnt, Mathias; Glauche, Ingmar; Greiner, Martin

2007-01-01

The observed structure of protein interaction networks is corrupted by many false positive/negative links. This observational incompleteness is abstracted as random link removal and a specific, experimentally motivated (spoke) link rearrangement. Their impact on the structural properties of gene-duplication-and-mutation network models is studied. For the degree distribution a curve collapse is found, showing no sensitive dependence on the link removal/rearrangement strengths and disallowing a quantitative extraction of model parameters. The spoke link rearrangement process moves other structural observables, like degree correlations, cluster coefficient and motif frequencies, closer to their counterparts extracted from the yeast data. This underlines the importance to take a precise modeling of the observational incompleteness into account when network structure models are to be quantitatively compared to data.

Retroviral gene transfer of an antisense construct against membrane type 1 matrix metalloproteinase reduces the invasiveness of rheumatoid arthritis synovial fibroblasts.

PubMed

Rutkauskaite, Edita; Volkmer, Dagmar; Shigeyama, Yukio; Schedel, Jörg; Pap, Geza; Müller-Ladner, Ulf; Meinecke, Ingmar; Alexander, Dorothea; Gay, Renate E; Drynda, Susanne; Neumann, Wolfram; Michel, Beat A; Aicher, Wilhelm K; Gay, Steffen; Pap, Thomas

2005-07-01

Membrane type 1 matrix metalloproteinase (MT1-MMP) is expressed prominently in rheumatoid arthritis synovial fibroblasts (RASFs), but the specific contribution of MT1-MMP to fibroblast-mediated destruction of articular cartilage is incompletely understood. This study used gene transfer of an antisense expression construct to assess the effects of MT1-MMP inhibition on the invasiveness of RASFs. Retroviral gene transfer of a pLXIN vector-based antisense RNA expression construct (MT1-MMPalphaS) to MT1-MMP was used to stably transduce RASFs. Levels of MT1-MMP RNA and protein were determined by quantitative polymerase chain reaction, Western blotting, and immunocytochemistry in MT1-MMPalphaS-transduced RASFs as well as in control cells, with monitoring for 60 days. The effects of MT1-MMPalphaS on the invasiveness of RASFs were analyzed in the SCID mouse co-implantation model of RA. MT1-MMPalphaS-transduced RASFs produced high levels of antisense RNA that exceeded endogenous levels of MT1-MMP messenger RNA by 15-fold and resulted in a down-regulation of MT1-MMP at the protein level. Inhibition of MT1-MMP production was maintained for 60 days and significantly reduced the invasiveness of RASFs in the SCID mouse model. Whereas prominent invasion into cartilage by non-transduced and mock-transduced RASFs was observed (mean invasion scores 3.0 and 3.1, respectively), MT1-MMPalphaS-transduced cells showed only moderate invasiveness (mean invasion score 1.8; P < 0.05). The data demonstrate that an antisense RNA expression construct against MT1-MMP can be generated and expressed in RASFs for at least 60 days. Inhibition of MT1-MMP significantly reduces the cartilage degradation by RASFs.

Scn2a deletion improves survival and brain-heart dynamics in the Kcna1-null mouse model of sudden unexpected death in epilepsy (SUDEP).

PubMed

Mishra, Vikas; Karumuri, Bharat K; Gautier, Nicole M; Liu, Rui; Hutson, Timothy N; Vanhoof-Villalba, Stephanie L; Vlachos, Ioannis; Iasemidis, Leonidas; Glasscock, Edward

2017-06-01

People with epilepsy have greatly increased probability of premature mortality due to sudden unexpected death in epilepsy (SUDEP). Identifying which patients are most at risk of SUDEP is hindered by a complex genetic etiology, incomplete understanding of the underlying pathophysiology and lack of prognostic biomarkers. Here we evaluated heterozygous Scn2a gene deletion (Scn2a+/-) as a protective genetic modifier in the Kcna1 knockout mouse (Kcna1-/-) model of SUDEP, while searching for biomarkers of SUDEP risk embedded in electroencephalography (EEG) and electrocardiography (ECG) recordings. The human epilepsy gene Kcna1 encodes voltage-gated Kv1.1 potassium channels that act to dampen neuronal excitability whereas Scn2a encodes voltage-gated Nav1.2 sodium channels important for action potential initiation and conduction. SUDEP-prone Kcna1-/- mice with partial genetic ablation of Nav1.2 channels (i.e. Scn2a+/-; Kcna1-/-) exhibited a two-fold increase in survival. Classical analysis of EEG and ECG recordings separately showed significantly decreased seizure durations in Scn2a+/-; Kcna1-/- mice compared with Kcna1-/- mice, without substantial modification of cardiac abnormalities. Novel analysis of the EEG and ECG together revealed a significant reduction in EEG-ECG association in Kcna1-/- mice compared with wild types, which was partially restored in Scn2a+/-; Kcna1-/- mice. The degree of EEG-ECG association was also proportional to the survival rate of mice across genotypes. These results show that Scn2a gene deletion acts as protective genetic modifier of SUDEP and suggest measures of brain-heart association as potential indices of SUDEP susceptibility. © The Author 2017. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Dysregulation of Ca(v)1.4 channels disrupts the maturation of photoreceptor synaptic ribbons in congenital stationary night blindness type 2.

PubMed

Liu, Xiaoni; Kerov, Vasily; Haeseleer, Françoise; Majumder, Anurima; Artemyev, Nikolai; Baker, Sheila A; Lee, Amy

2013-01-01

Mutations in the gene encoding Cav 1.4, CACNA1F, are associated with visual disorders including X-linked incomplete congenital stationary night blindness type 2 (CSNB2). In mice lacking Cav 1.4 channels, there are defects in the development of "ribbon" synapses formed between photoreceptors (PRs) and second-order neurons. However, many CSNB2 mutations disrupt the function rather than expression of Cav 1.4 channels. Whether defects in PR synapse development due to altered Cav 1.4 function are common features contributing to the pathogenesis of CSNB2 is unknown. To resolve this issue, we profiled changes in the subcellular distribution of Cav 1.4 channels and synapse morphology during development in wild-type (WT) mice and mouse models of CSNB2. Using Cav 1.4-selective antibodies, we found that Cav 1.4 channels associate with ribbon precursors early in development and are concentrated at both rod and cone PR synapses in the mature retina. In mouse models of CSNB2 in which the voltage-dependence of Cav 1.4 activation is either enhanced (Cav 1.4I756T) or inhibited (CaBP4 KO), the initial stages of PR synaptic ribbon formation are largely unaffected. However, after postnatal day 13, many PR ribbons retain the immature morphology. This synaptic abnormality corresponds in severity to the defect in synaptic transmission in the adult mutant mice, suggesting that lack of sufficient mature synapses contributes to vision impairment in Cav 1.4I756T and CaBP4 KO mice. Our results demonstrate the importance of proper Cav 1.4 function for efficient PR synapse maturation, and that dysregulation of Cav 1.4 channels in CSNB2 may have synaptopathic consequences.

Paradoxical Motor Recovery From a First Stroke After Induction of a Second Stroke: Reopening a Postischemic Sensitive Period.

PubMed

Zeiler, Steven R; Hubbard, Robert; Gibson, Ellen M; Zheng, Tony; Ng, Kwan; O'Brien, Richard; Krakauer, John W

2016-09-01

Prior studies have suggested that after stroke there is a time-limited period of increased responsiveness to training as a result of heightened plasticity-a sensitive period thought to be induced by ischemia itself. Using a mouse model, we have previously shown that most training-associated recovery after a caudal forelimb area (CFA) stroke occurs in the first week and is attributable to reorganization in a medial premotor area (AGm). The existence of a stroke-induced sensitive period leads to the counterintuitive prediction that a second stroke should reopen this window and promote full recovery from the first stroke. To test this prediction, we induced a second stroke in the AGm of mice with incomplete recovery after a first stroke in CFA. Mice were trained to perform a skilled prehension (reach-to-grasp) task to an asymptotic level of performance, after which they underwent photocoagulation-induced stroke in CFA. After a 7-day poststroke delay, the mice were then retrained to asymptote. We then induced a second stroke in the AGm, and after only a 1-day delay, retrained the mice. Recovery of prehension was incomplete when training was started after a 7-day poststroke delay and continued for 19 days. However, a second focal stroke in the AGm led to a dramatic response to 9 days of training, with full recovery to normal levels of performance. New ischemia can reopen a sensitive period of heightened responsiveness to training and mediate full recovery from a previous stroke. © The Author(s) 2015.

Finding mouse models of human lymphomas and leukemia's using the Jackson laboratory mouse tumor biology database.

PubMed

Begley, Dale A; Sundberg, John P; Krupke, Debra M; Neuhauser, Steven B; Bult, Carol J; Eppig, Janan T; Morse, Herbert C; Ward, Jerrold M

2015-12-01

Many mouse models have been created to study hematopoietic cancer types. There are over thirty hematopoietic tumor types and subtypes, both human and mouse, with various origins, characteristics and clinical prognoses. Determining the specific type of hematopoietic lesion produced in a mouse model and identifying mouse models that correspond to the human subtypes of these lesions has been a continuing challenge for the scientific community. The Mouse Tumor Biology Database (MTB; http://tumor.informatics.jax.org) is designed to facilitate use of mouse models of human cancer by providing detailed histopathologic and molecular information on lymphoma subtypes, including expertly annotated, on line, whole slide scans, and providing a repository for storing information on and querying these data for specific lymphoma models. Copyright © 2015 Elsevier Inc. All rights reserved.

Mouse models rarely mimic the transcriptome of human neurodegenerative diseases: A systematic bioinformatics-based critique of preclinical models.

PubMed

Burns, Terry C; Li, Matthew D; Mehta, Swapnil; Awad, Ahmed J; Morgan, Alexander A

2015-07-15

Translational research for neurodegenerative disease depends intimately upon animal models. Unfortunately, promising therapies developed using mouse models mostly fail in clinical trials, highlighting uncertainty about how well mouse models mimic human neurodegenerative disease at the molecular level. We compared the transcriptional signature of neurodegeneration in mouse models of Alzheimer׳s disease (AD), Parkinson׳s disease (PD), Huntington׳s disease (HD) and amyotrophic lateral sclerosis (ALS) to human disease. In contrast to aging, which demonstrated a conserved transcriptome between humans and mice, only 3 of 19 animal models showed significant enrichment for gene sets comprising the most dysregulated up- and down-regulated human genes. Spearman׳s correlation analysis revealed even healthy human aging to be more closely related to human neurodegeneration than any mouse model of AD, PD, ALS or HD. Remarkably, mouse models frequently upregulated stress response genes that were consistently downregulated in human diseases. Among potential alternate models of neurodegeneration, mouse prion disease outperformed all other disease-specific models. Even among the best available animal models, conserved differences between mouse and human transcriptomes were found across multiple animal model versus human disease comparisons, surprisingly, even including aging. Relative to mouse models, mouse disease signatures demonstrated consistent trends toward preserved mitochondrial function protein catabolism, DNA repair responses, and chromatin maintenance. These findings suggest a more complex and multifactorial pathophysiology in human neurodegeneration than is captured through standard animal models, and suggest that even among conserved physiological processes such as aging, mice are less prone to exhibit neurodegeneration-like changes. This work may help explain the poor track record of mouse-based translational therapies for neurodegeneration and provides a path forward to critically evaluate and improve animal models of human disease. Copyright © 2015 Elsevier B.V. All rights reserved.

Activity-Based Protein Profiling of Organophosphorus and Thiocarbamate Pesticides Reveals Multiple Serine Hydrolase Targets in Mouse Brain

PubMed Central

NOMURA, DANIEL K.; CASIDA, JOHN E.

2010-01-01

Organophosphorus (OP) and thiocarbamate (TC) agrochemicals are used worldwide as insecticides, herbicides, and fungicides, but their safety assessment in terms of potential off-targets remains incomplete. In this study, we used a chemoproteomic platform, termed activity-based protein profiling, to broadly define serine hydrolase targets in mouse brain of a panel of 29 OP and TC pesticides. Among the secondary targets identified, enzymes involved in degradation of endocannabinoid signaling lipids, monoacylglycerol lipase and fatty acid amide hydrolase, were inhibited by several OP and TC pesticides. Blockade of these two enzymes led to elevations in brain endocannabinoid levels and dysregulated brain arachidonate metabolism. Other secondary targets include enzymes thought to also play important roles in the nervous system and unannotated proteins. This study reveals a multitude of secondary targets for OP and TC pesticides and underscores the utility of chemoproteomic platforms in gaining insights into biochemical pathways that are perturbed by these toxicants. PMID:21341672

Simultaneous submicrometric 3D imaging of the micro-vascular network and the neuronal system in a mouse spinal cord

PubMed Central

Fratini, Michela; Bukreeva, Inna; Campi, Gaetano; Brun, Francesco; Tromba, Giuliana; Modregger, Peter; Bucci, Domenico; Battaglia, Giuseppe; Spanò, Raffaele; Mastrogiacomo, Maddalena; Requardt, Herwig; Giove, Federico; Bravin, Alberto; Cedola, Alessia

2015-01-01

Faults in vascular (VN) and neuronal networks of spinal cord are responsible for serious neurodegenerative pathologies. Because of inadequate investigation tools, the lacking knowledge of the complete fine structure of VN and neuronal system represents a crucial problem. Conventional 2D imaging yields incomplete spatial coverage leading to possible data misinterpretation, whereas standard 3D computed tomography imaging achieves insufficient resolution and contrast. We show that X-ray high-resolution phase-contrast tomography allows the simultaneous visualization of three-dimensional VN and neuronal systems of ex-vivo mouse spinal cord at scales spanning from millimeters to hundreds of nanometers, with nor contrast agent nor sectioning and neither destructive sample-preparation. We image both the 3D distribution of micro-capillary network and the micrometric nerve fibers, axon-bundles and neuron soma. Our approach is very suitable for pre-clinical investigation of neurodegenerative pathologies and spinal-cord-injuries, in particular to resolve the entangled relationship between VN and neuronal system. PMID:25686728

Nanoparticulate carbon black in cigarette smoke induces DNA cleavage and Th17-mediated emphysema.

PubMed

You, Ran; Lu, Wen; Shan, Ming; Berlin, Jacob M; Samuel, Errol Lg; Marcano, Daniela C; Sun, Zhengzong; Sikkema, William Ka; Yuan, Xiaoyi; Song, Lizhen; Hendrix, Amanda Y; Tour, James M; Corry, David B; Kheradmand, Farrah

2015-10-05

Chronic inhalation of cigarette smoke is the major cause of sterile inflammation and pulmonary emphysema. The effect of carbon black (CB), a universal constituent of smoke derived from the incomplete combustion of organic material, in smokers and non-smokers is less known. In this study, we show that insoluble nanoparticulate carbon black (nCB) accumulates in human myeloid dendritic cells (mDCs) from emphysematous lung and in CD11c(+) lung antigen presenting cells (APC) of mice exposed to smoke. Likewise, nCB intranasal administration induced emphysema in mouse lungs. Delivered by smoking or intranasally, nCB persisted indefinitely in mouse lung, activated lung APCs, and promoted T helper 17 cell differentiation through double-stranded DNA break (DSB) and ASC-mediated inflammasome assembly in phagocytes. Increasing the polarity or size of CB mitigated many adverse effects. Thus, nCB causes sterile inflammation, DSB, and emphysema and explains adverse health outcomes seen in smokers while implicating the dangers of nCB exposure in non-smokers.

Aberrant Upregulation of Astroglial Ceramide Potentiates Oligodendrocyte Injury

PubMed Central

Kim, SunJa; Steelman, Andrew J.; Zhang, Yumin; Kinney, Hannah C.; Li, Jianrong

2015-01-01

Oligodendroglial injury is a pathological hallmark of many human white matter diseases, including multiple sclerosis and periventricular leukomalacia. Critical regulatory mechanisms of oligodendroglia destruction, however, remain incompletely understood. Ceramide, a bioactive sphingolipid pivotal to sphingolipid metabolism pathways, regulates cell death in response to diverse stimuli and has been implicated in neurodegenerative disorders. We report here that ceramide accumulates in reactive astrocytes in active lesions of multiple sclerosis and periventricular leukomalacia, as well as in animal models of demyelination. Serine palmitoyltransferase, the rate-limiting enzyme for ceramide de novo biosynthesis, was consistently upregulated in reactive astrocytes in the cuprizone mouse model of demyelination. Mass spectrometry confirmed the upregulation of specific ceramides during demyelination and revealed a concomitant increase of sphingosine as well as a suppression of sphingosine-1-phosphate, a potent signaling molecule with key roles in cell survival and mitogenesis. Importantly, this altered sphingolipid metabolism during demyelination was restored upon active remyelination. In culture, ceramide acted synergistically with tumor necrosis factor leading to apoptotic death of oligodendroglia in an astrocyte-dependent manner. Taken together, our findings implicate that disturbed sphingolipid pathways in reactive astrocytes may indirectly contribute to oligodendroglial injury in cerebral white matter disorders. PMID:21615590

TOPSIS-based consensus model for group decision-making with incomplete interval fuzzy preference relations.

PubMed

Liu, Fang; Zhang, Wei-Guo

2014-08-01

Due to the vagueness of real-world environments and the subjective nature of human judgments, it is natural for experts to estimate their judgements by using incomplete interval fuzzy preference relations. In this paper, based on the technique for order preference by similarity to ideal solution method, we present a consensus model for group decision-making (GDM) with incomplete interval fuzzy preference relations. To do this, we first define a new consistency measure for incomplete interval fuzzy preference relations. Second, a goal programming model is proposed to estimate the missing interval preference values and it is guided by the consistency property. Third, an ideal interval fuzzy preference relation is constructed by using the induced ordered weighted averaging operator, where the associated weights of characterizing the operator are based on the defined consistency measure. Fourth, a similarity degree between complete interval fuzzy preference relations and the ideal one is defined. The similarity degree is related to the associated weights, and used to aggregate the experts' preference relations in such a way that more importance is given to ones with the higher similarity degree. Finally, a new algorithm is given to solve the GDM problem with incomplete interval fuzzy preference relations, which is further applied to partnership selection in formation of virtual enterprises.

Toll-like Receptor 4-mediated Endoplasmic Reticulum Stress in Intestinal Crypts Induces Necrotizing Enterocolitis*

PubMed Central

Afrazi, Amin; Branca, Maria F.; Sodhi, Chhinder P.; Good, Misty; Yamaguchi, Yukihiro; Egan, Charlotte E.; Lu, Peng; Jia, Hongpeng; Shaffiey, Shahab; Lin, Joyce; Ma, Congrong; Vincent, Garrett; Prindle, Thomas; Weyandt, Samantha; Neal, Matthew D.; Ozolek, John A.; Wiersch, John; Tschurtschenthaler, Markus; Shiota, Chiyo; Gittes, George K.; Billiar, Timothy R.; Mollen, Kevin; Kaser, Arthur; Blumberg, Richard; Hackam, David J.

2014-01-01

The cellular cues that regulate the apoptosis of intestinal stem cells (ISCs) remain incompletely understood, yet may play a role in diseases characterized by ISC loss including necrotizing enterocolitis (NEC). Toll-like receptor-4 (TLR4) was recently found to be expressed on ISCs, where its activation leads to ISC apoptosis through mechanisms that remain incompletely explained. We now hypothesize that TLR4 induces endoplasmic reticulum (ER) stress within ISCs, leading to their apoptosis in NEC pathogenesis, and that high ER stress within the premature intestine predisposes to NEC development. Using transgenic mice and cultured enteroids, we now demonstrate that TLR4 induces ER stress within Lgr5 (leucine-rich repeat-containing G-protein-coupled receptor 5)-positive ISCs, resulting in crypt apoptosis. TLR4 signaling within crypts was required, because crypt ER stress and apoptosis occurred in TLR4ΔIEC-OVER mice expressing TLR4 only within intestinal crypts and epithelium, but not TLR4ΔIEC mice lacking intestinal TLR4. TLR4-mediated ER stress and apoptosis of ISCs required PERK (protein kinase-related PKR-like ER kinase), CHOP (C/EBP homologous protein), and MyD88 (myeloid differentiation primary response gene 88), but not ATF6 (activating transcription factor 6) or XBP1 (X-box-binding protein 1). Human and mouse NEC showed high crypt ER stress and apoptosis, whereas genetic inhibition of PERK or CHOP attenuated ER stress, crypt apoptosis, and NEC severity. Strikingly, using intragastric delivery into fetal mouse intestine, prevention of ER stress reduced TLR4-mediated ISC apoptosis and mucosal disruption. These findings identify a novel link between TLR4-induced ER stress and ISC apoptosis in NEC pathogenesis and suggest that increased ER stress within the premature bowel predisposes to NEC development. PMID:24519940

Toll-like receptor 4-mediated endoplasmic reticulum stress in intestinal crypts induces necrotizing enterocolitis.

PubMed

Afrazi, Amin; Branca, Maria F; Sodhi, Chhinder P; Good, Misty; Yamaguchi, Yukihiro; Egan, Charlotte E; Lu, Peng; Jia, Hongpeng; Shaffiey, Shahab; Lin, Joyce; Ma, Congrong; Vincent, Garrett; Prindle, Thomas; Weyandt, Samantha; Neal, Matthew D; Ozolek, John A; Wiersch, John; Tschurtschenthaler, Markus; Shiota, Chiyo; Gittes, George K; Billiar, Timothy R; Mollen, Kevin; Kaser, Arthur; Blumberg, Richard; Hackam, David J

2014-04-04

The cellular cues that regulate the apoptosis of intestinal stem cells (ISCs) remain incompletely understood, yet may play a role in diseases characterized by ISC loss including necrotizing enterocolitis (NEC). Toll-like receptor-4 (TLR4) was recently found to be expressed on ISCs, where its activation leads to ISC apoptosis through mechanisms that remain incompletely explained. We now hypothesize that TLR4 induces endoplasmic reticulum (ER) stress within ISCs, leading to their apoptosis in NEC pathogenesis, and that high ER stress within the premature intestine predisposes to NEC development. Using transgenic mice and cultured enteroids, we now demonstrate that TLR4 induces ER stress within Lgr5 (leucine-rich repeat-containing G-protein-coupled receptor 5)-positive ISCs, resulting in crypt apoptosis. TLR4 signaling within crypts was required, because crypt ER stress and apoptosis occurred in TLR4(ΔIEC-OVER) mice expressing TLR4 only within intestinal crypts and epithelium, but not TLR4(ΔIEC) mice lacking intestinal TLR4. TLR4-mediated ER stress and apoptosis of ISCs required PERK (protein kinase-related PKR-like ER kinase), CHOP (C/EBP homologous protein), and MyD88 (myeloid differentiation primary response gene 88), but not ATF6 (activating transcription factor 6) or XBP1 (X-box-binding protein 1). Human and mouse NEC showed high crypt ER stress and apoptosis, whereas genetic inhibition of PERK or CHOP attenuated ER stress, crypt apoptosis, and NEC severity. Strikingly, using intragastric delivery into fetal mouse intestine, prevention of ER stress reduced TLR4-mediated ISC apoptosis and mucosal disruption. These findings identify a novel link between TLR4-induced ER stress and ISC apoptosis in NEC pathogenesis and suggest that increased ER stress within the premature bowel predisposes to NEC development.

An information propagation model considering incomplete reading behavior in microblog

NASA Astrophysics Data System (ADS)

Su, Qiang; Huang, Jiajia; Zhao, Xiande

2015-02-01

Microblog is one of the most popular communication channels on the Internet, and has already become the third largest source of news and public opinions in China. Although researchers have studied the information propagation in microblog using the epidemic models, previous studies have not considered the incomplete reading behavior among microblog users. Therefore, the model cannot fit the real situations well. In this paper, we proposed an improved model entitled Microblog-Susceptible-Infected-Removed (Mb-SIR) for information propagation by explicitly considering the user's incomplete reading behavior. We also tested the effectiveness of the model using real data from Sina Microblog. We demonstrate that the new proposed model is more accurate in describing the information propagation in microblog. In addition, we also investigate the effects of the critical model parameters, e.g., reading rate, spreading rate, and removed rate through numerical simulations. The simulation results show that, compared with other parameters, reading rate plays the most influential role in the information propagation performance in microblog.

System parameters for erythropoiesis control model: Comparison of normal values in human and mouse model

NASA Technical Reports Server (NTRS)

1979-01-01

The computer model for erythropoietic control was adapted to the mouse system by altering system parameters originally given for the human to those which more realistically represent the mouse. Parameter values were obtained from a variety of literature sources. Using the mouse model, the mouse was studied as a potential experimental model for spaceflight. Simulation studies of dehydration and hypoxia were performed. A comparison of system parameters for the mouse and human models is presented. Aside from the obvious differences expected in fluid volumes, blood flows and metabolic rates, larger differences were observed in the following: erythrocyte life span, erythropoietin half-life, and normal arterial pO2.

Stochastic Online Learning in Dynamic Networks under Unknown Models

DTIC Science & Technology

2016-08-02

Repeated Game with Incomplete Information, IEEE International Conference on Acoustics, Speech, and Signal Processing. 20-MAR-16, Shanghai, China...in a game theoretic framework for the application of multi-seller dynamic pricing with unknown demand models. We formulated the problem as an...infinitely repeated game with incomplete information and developed a dynamic pricing strategy referred to as Competitive and Cooperative Demand Learning

Human mammary microenvironment better regulates the biology of human breast cancer in humanized mouse model.

PubMed

Zheng, Ming-Jie; Wang, Jue; Xu, Lu; Zha, Xiao-Ming; Zhao, Yi; Ling, Li-Jun; Wang, Shui

2015-02-01

During the past decades, many efforts have been made in mimicking the clinical progress of human cancer in mouse models. Previously, we developed a human breast tissue-derived (HB) mouse model. Theoretically, it may mimic the interactions between "species-specific" mammary microenvironment of human origin and human breast cancer cells. However, detailed evidences are absent. The present study (in vivo, cellular, and molecular experiments) was designed to explore the regulatory role of human mammary microenvironment in the progress of human breast cancer cells. Subcutaneous (SUB), mammary fat pad (MFP), and HB mouse models were developed for in vivo comparisons. Then, the orthotopic tumor masses from three different mouse models were collected for primary culture. Finally, the biology of primary cultured human breast cancer cells was compared by cellular and molecular experiments. Results of in vivo mouse models indicated that human breast cancer cells grew better in human mammary microenvironment. Cellular and molecular experiments confirmed that primary cultured human breast cancer cells from HB mouse model showed a better proliferative and anti-apoptotic biology than those from SUB to MFP mouse models. Meanwhile, primary cultured human breast cancer cells from HB mouse model also obtained the migratory and invasive biology for "species-specific" tissue metastasis to human tissues. Comprehensive analyses suggest that "species-specific" mammary microenvironment of human origin better regulates the biology of human breast cancer cells in our humanized mouse model of breast cancer, which is more consistent with the clinical progress of human breast cancer.

Parathyroid hormone-related peptide and the hair cycle - is it the agonists or the antagonists that cause hair growth?

PubMed

Gensure, Robert C

2014-12-01

While the effects of PTHrP have been studied for almost 20 years, most of these studies have focused on effects on the termination of the anagen phase, giving an incomplete picture of the overall effect of PTHrP on the hair cycle. PTHrP was determined in several experimental models to promote transition of hair follicles from anagen to catagen phase, which by itself would suggest that PTHrP blockade might prolong the anagen phase and promote hair growth. However, clinical trials with topically applied PTHrP antagonists have been disappointing, leading to a reconsideration of this model. Additional studies performed in mouse models where hair follicles are damaged (alopecia areata, chemotherapy-induced alopecia) suggest that PTHrP has effects early in the hair cycle as well, promoting hair follicles' entry into anagen phase and initiates the hair cycle. While the mechanism of this has yet to be elucidated, it may involve activation of the Wnt pathway. Thus, the overall effect of PTHrP is to stimulate and accelerate the hair cycle, and in the more clinically relevant models of hair loss where hair follicles have been damaged or become quiescent, it is the agonists, not the antagonists, which would be expected to promote hair growth. © 2014 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

The Mouse Tumor Biology Database: A Comprehensive Resource for Mouse Models of Human Cancer.

PubMed

Krupke, Debra M; Begley, Dale A; Sundberg, John P; Richardson, Joel E; Neuhauser, Steven B; Bult, Carol J

2017-11-01

Research using laboratory mice has led to fundamental insights into the molecular genetic processes that govern cancer initiation, progression, and treatment response. Although thousands of scientific articles have been published about mouse models of human cancer, collating information and data for a specific model is hampered by the fact that many authors do not adhere to existing annotation standards when describing models. The interpretation of experimental results in mouse models can also be confounded when researchers do not factor in the effect of genetic background on tumor biology. The Mouse Tumor Biology (MTB) database is an expertly curated, comprehensive compendium of mouse models of human cancer. Through the enforcement of nomenclature and related annotation standards, MTB supports aggregation of data about a cancer model from diverse sources and assessment of how genetic background of a mouse strain influences the biological properties of a specific tumor type and model utility. Cancer Res; 77(21); e67-70. ©2017 AACR . ©2017 American Association for Cancer Research.

Enrichment of cardiac differentiation of mouse embryonic stem cells by optimizing the hanging drop method.

PubMed

Chen, Ming; Lin, Yong-Qing; Xie, Shuang-Lun; Wu, Hong-Fu; Wang, Jing-Feng

2011-04-01

Hanging drop (HD) culture is used to induce differentiation of embryonic stem cells (ESCs) into other cell types including cardiomyocytes. However, the factors affecting cardiac differentiation of ESCs with this method remain incompletely understood. We have investigated the effects of the starting number of ESCs in embryoid bodies (EBs) and the time of EB adherence to gelatin-coated plates on cardiac differentiation: cardiac differentiation was increased in the EBs by a larger number of ESCs and was decreased by plating EBs at day 4 or earlier. These two factors can thus be optimized to enrich the cardiac differentiation in ESCs using the HD method.

Modeling non-syndromic autism and the impact of TRPC6 disruption in human neurons.

PubMed

Griesi-Oliveira, K; Acab, A; Gupta, A R; Sunaga, D Y; Chailangkarn, T; Nicol, X; Nunez, Y; Walker, M F; Murdoch, J D; Sanders, S J; Fernandez, T V; Ji, W; Lifton, R P; Vadasz, E; Dietrich, A; Pradhan, D; Song, H; Ming, G-L; Gu, X; Haddad, G; Marchetto, M C N; Spitzer, N; Passos-Bueno, M R; State, M W; Muotri, A R

2015-11-01

An increasing number of genetic variants have been implicated in autism spectrum disorders (ASDs), and the functional study of such variants will be critical for the elucidation of autism pathophysiology. Here, we report a de novo balanced translocation disruption of TRPC6, a cation channel, in a non-syndromic autistic individual. Using multiple models, such as dental pulp cells, induced pluripotent stem cell (iPSC)-derived neuronal cells and mouse models, we demonstrate that TRPC6 reduction or haploinsufficiency leads to altered neuronal development, morphology and function. The observed neuronal phenotypes could then be rescued by TRPC6 complementation and by treatment with insulin-like growth factor-1 or hyperforin, a TRPC6-specific agonist, suggesting that ASD individuals with alterations in this pathway may benefit from these drugs. We also demonstrate that methyl CpG binding protein-2 (MeCP2) levels affect TRPC6 expression. Mutations in MeCP2 cause Rett syndrome, revealing common pathways among ASDs. Genetic sequencing of TRPC6 in 1041 ASD individuals and 2872 controls revealed significantly more nonsynonymous mutations in the ASD population, and identified loss-of-function mutations with incomplete penetrance in two patients. Taken together, these findings suggest that TRPC6 is a novel predisposing gene for ASD that may act in a multiple-hit model. This is the first study to use iPSC-derived human neurons to model non-syndromic ASD and illustrate the potential of modeling genetically complex sporadic diseases using such cells.

Modeling non-syndromic autism and the impact of TRPC6 disruption in human neurons

PubMed Central

Griesi-Oliveira, Karina; Acab, Allan; Gupta, Abha R.; Sunaga, Daniele Yumi; Chailangkarn, Thanathom; Nicol, Xavier; Nunez, Yanelli; Walker, Michael F.; Murdoch, John D.; Sanders, Stephan J.; Fernandez, Thomas V.; Ji, Weizhen; Lifton, Richard P.; Vadasz, Estevão; Dietrich, Alexander; Pradhan, Dennis; Song, Hongjun; Ming, Guo-li; Guoe, Xiang; Haddad, Gabriel; Marchetto, Maria C. N.; Spitzer, Nicholas; Passos-Bueno, Maria Rita; State, Matthew W.; Muotri, Alysson R.

2014-01-01

An increasing number of genetic variants have been implicated in autism spectrum disorders (ASD), and the functional study of such variants will be critical for the elucidation of autism pathophysiology. Here, we report a de novo balanced translocation disruption of TRPC6, a cation channel, in a non-syndromic autistic individual. Using multiple models, such as dental pulp cells, iPSC-derived neuronal cells and mouse models, we demonstrate that TRPC6 reduction or haploinsufficiency leads to altered neuronal development, morphology, and function. The observed neuronal phenotypes could then be rescued by TRPC6 complementation and by treatment with IGF1 or hyperforin, a TRPC6-specific agonist, suggesting that ASD individuals with alterations in this pathway might benefit from these drugs. We also demonstrate that MeCP2 levels affect TRPC6 expression. Mutations in MeCP2 cause Rett syndrome, revealing common pathways among ASDs. Genetic sequencing of TRPC6 in 1041 ASD individuals and 2872 controls revealed significantly more nonsynonymous mutations in the ASD population, and identified loss-of-function mutations with incomplete penetrance in two patients. Taken together, these findings suggest that TRPC6 is a novel predisposing gene for ASD that may act in a multiple-hit model. This is the first study to use iPSC-derived human neurons to model non-syndromic ASD and illustrate the potential of modeling genetically complex sporadic diseases using such cells. PMID:25385366

The incomplete inverse and its applications to the linear least squares problem

NASA Technical Reports Server (NTRS)

Morduch, G. E.

1977-01-01

A modified matrix product is explained, and it is shown that this product defiles a group whose inverse is called the incomplete inverse. It was proven that the incomplete inverse of an augmented normal matrix includes all the quantities associated with the least squares solution. An answer is provided to the problem that occurs when the data residuals are too large and when insufficient data to justify augmenting the model are available.

Drug discovery in prostate cancer mouse models.

PubMed

Valkenburg, Kenneth C; Pienta, Kenneth J

2015-01-01

The mouse is an important, though imperfect, organism with which to model human disease and to discover and test novel drugs in a preclinical setting. Many experimental strategies have been used to discover new biological and molecular targets in the mouse, with the hopes of translating these discoveries into novel drugs to treat prostate cancer in humans. Modeling prostate cancer in the mouse, however, has been challenging, and often drugs that work in mice have failed in human trials. The authors discuss the similarities and differences between mice and men; the types of mouse models that exist to model prostate cancer; practical questions one must ask when using a mouse as a model; and potential reasons that drugs do not often translate to humans. They also discuss the current value in using mouse models for drug discovery to treat prostate cancer and what needs are still unmet in field. With proper planning and following practical guidelines by the researcher, the mouse is a powerful experimental tool. The field lacks genetically engineered metastatic models, and xenograft models do not allow for the study of the immune system during the metastatic process. There remain several important limitations to discovering and testing novel drugs in mice for eventual human use, but these can often be overcome. Overall, mouse modeling is an essential part of prostate cancer research and drug discovery. Emerging technologies and better and ever-increasing forms of communication are moving the field in a hopeful direction.

An improved swarm optimization for parameter estimation and biological model selection.

PubMed

Abdullah, Afnizanfaizal; Deris, Safaai; Mohamad, Mohd Saberi; Anwar, Sohail

2013-01-01

One of the key aspects of computational systems biology is the investigation on the dynamic biological processes within cells. Computational models are often required to elucidate the mechanisms and principles driving the processes because of the nonlinearity and complexity. The models usually incorporate a set of parameters that signify the physical properties of the actual biological systems. In most cases, these parameters are estimated by fitting the model outputs with the corresponding experimental data. However, this is a challenging task because the available experimental data are frequently noisy and incomplete. In this paper, a new hybrid optimization method is proposed to estimate these parameters from the noisy and incomplete experimental data. The proposed method, called Swarm-based Chemical Reaction Optimization, integrates the evolutionary searching strategy employed by the Chemical Reaction Optimization, into the neighbouring searching strategy of the Firefly Algorithm method. The effectiveness of the method was evaluated using a simulated nonlinear model and two biological models: synthetic transcriptional oscillators, and extracellular protease production models. The results showed that the accuracy and computational speed of the proposed method were better than the existing Differential Evolution, Firefly Algorithm and Chemical Reaction Optimization methods. The reliability of the estimated parameters was statistically validated, which suggests that the model outputs produced by these parameters were valid even when noisy and incomplete experimental data were used. Additionally, Akaike Information Criterion was employed to evaluate the model selection, which highlighted the capability of the proposed method in choosing a plausible model based on the experimental data. In conclusion, this paper presents the effectiveness of the proposed method for parameter estimation and model selection problems using noisy and incomplete experimental data. This study is hoped to provide a new insight in developing more accurate and reliable biological models based on limited and low quality experimental data.

1.5Mb deletion of chromosome 4p16.3 associated with postnatal growth delay, psychomotor impairment, epilepsy, impulsive behavior and asynchronous skeletal development.

PubMed

Misceo, D; Barøy, T; Helle, J R; Braaten, O; Fannemel, M; Frengen, E

2012-10-01

Several Wolf-Hirschhorn syndrome patients have been studied, mouse models for a few candidate genes have been constructed and two WHS critical regions have been postulated, but the molecular basis of the syndrome remains poorly understood. Single gene contributions to phenotypes of microdeletion syndromes have often been based on the study of patients carrying small, atypical deletions. We report a 5-year-old girl harboring an atypical 1.5Mb del4p16.3 and review seven previously published patients carrying a similar deletion. They show a variable clinical presentation and the only consistent feature is post-natal growth delay. However, four of eight patients carry a ring (4), and ring chromosomes in general are associated with growth deficiency. The Greek helmet profile is absent, although a trend towards common dysmorphic features exists. Variable expressivity and incomplete penetrance might play a role in WHS, resulting in difficult clinical diagnosis and challenge in understanding of the genotype/phenotype correlation. Copyright © 2012 Elsevier B.V. All rights reserved.

Binocular Goggle Augmented Imaging and Navigation System provides real-time fluorescence image guidance for tumor resection and sentinel lymph node mapping

NASA Astrophysics Data System (ADS)

B. Mondal, Suman; Gao, Shengkui; Zhu, Nan; Sudlow, Gail P.; Liang, Kexian; Som, Avik; Akers, Walter J.; Fields, Ryan C.; Margenthaler, Julie; Liang, Rongguang; Gruev, Viktor; Achilefu, Samuel

2015-07-01

The inability to identify microscopic tumors and assess surgical margins in real-time during oncologic surgery leads to incomplete tumor removal, increases the chances of tumor recurrence, and necessitates costly repeat surgery. To overcome these challenges, we have developed a wearable goggle augmented imaging and navigation system (GAINS) that can provide accurate intraoperative visualization of tumors and sentinel lymph nodes in real-time without disrupting normal surgical workflow. GAINS projects both near-infrared fluorescence from tumors and the natural color images of tissue onto a head-mounted display without latency. Aided by tumor-targeted contrast agents, the system detected tumors in subcutaneous and metastatic mouse models with high accuracy (sensitivity = 100%, specificity = 98% ± 5% standard deviation). Human pilot studies in breast cancer and melanoma patients using a near-infrared dye show that the GAINS detected sentinel lymph nodes with 100% sensitivity. Clinical use of the GAINS to guide tumor resection and sentinel lymph node mapping promises to improve surgical outcomes, reduce rates of repeat surgery, and improve the accuracy of cancer staging.

Multi-spectral fluorescent reporter influenza viruses (Color-flu) as powerful tools for in vivo studies

PubMed Central

Fukuyama, Satoshi; Katsura, Hiroaki; Zhao, Dongming; Ozawa, Makoto; Ando, Tomomi; Shoemaker, Jason E.; Ishikawa, Izumi; Yamada, Shinya; Neumann, Gabriele; Watanabe, Shinji; Kitano, Hiroaki; Kawaoka, Yoshihiro

2015-01-01

Seasonal influenza A viruses cause annual epidemics of respiratory disease; highly pathogenic avian H5N1 and the recently emerged H7N9 viruses cause severe infections in humans, often with fatal outcomes. Although numerous studies have addressed the pathogenicity of influenza viruses, influenza pathogenesis remains incompletely understood. Here we generate influenza viruses expressing fluorescent proteins of different colours (‘Color-flu’ viruses) to facilitate the study of viral infection in in vivo models. On adaptation to mice, stable expression of the fluorescent proteins in infected animals allows their detection by different types of microscopy and by flow cytometry. We use this system to analyse the progression of viral spread in mouse lungs, for live imaging of virus-infected cells, and for differential gene expression studies in virus antigen-positive and virus antigen-negative live cells in the lungs of Color-flu-infected mice. Collectively, Color-flu viruses are powerful tools to analyse virus infections at the cellular level in vivo to better understand influenza pathogenesis. PMID:25807527

A different regional response by mouse oligodendrocyte progenitor cells (OPCs) to high-dose X-irradiation has consequences for repopulating OPC-depleted normal tissue.

PubMed

Irvine, Karen-Amanda; Blakemore, William F

2007-01-01

This study was designed to investigate whether the residual, dysfunctional oligodendrocyte progenitor cells (OPCs) observed following X-irradiation of the mouse spinal cord [D. M. Chari et al. (2003) Exp. Neurol., 198, 145-153], the presence of which prevented the endogenous repopulation of these areas from normal tissue, reflects a general response of OPCs in the mouse central nervous system (CNS) to X-irradiation. The brains of adult mice were exposed to 40 Gy of X-irradiation and the effect of X-irradiation on the OPCs was assessed up to 4 weeks post-irradiation using anti-NG2 antibodies. X-irradiation resulted in almost complete depletion of OPCs within the telencephalon (cortex, corpus callosum and hippocampus) by 7 days post-irradiation, which was followed by progressive repopulation of OPCs from non-irradiated areas of the cortex. By contrast, within the lower brain centres (the diencephalon and mesencephalon) OPC loss occurred much more slowly so that 26% of the OPCs still remained 4 weeks after X-irradiation. The consequence of this heterogeneous response to X-irradiation was that whereas transplanted and endogenous OPCs rapidly established themselves in the OPC-depleted telencephalon this did not occur in the areas where there was incomplete depletion of endogenous OPCs. Our findings confirm not only the requirement for almost complete OPC depletion in order to establish transplanted OPCs in normal tissue but also highlight a heterogeneity of progenitor populations in different areas of the mouse CNS.

Orthology for comparative genomics in the mouse genome database.

PubMed

Dolan, Mary E; Baldarelli, Richard M; Bello, Susan M; Ni, Li; McAndrews, Monica S; Bult, Carol J; Kadin, James A; Richardson, Joel E; Ringwald, Martin; Eppig, Janan T; Blake, Judith A

2015-08-01

The mouse genome database (MGD) is the model organism database component of the mouse genome informatics system at The Jackson Laboratory. MGD is the international data resource for the laboratory mouse and facilitates the use of mice in the study of human health and disease. Since its beginnings, MGD has included comparative genomics data with a particular focus on human-mouse orthology, an essential component of the use of mouse as a model organism. Over the past 25 years, novel algorithms and addition of orthologs from other model organisms have enriched comparative genomics in MGD data, extending the use of orthology data to support the laboratory mouse as a model of human biology. Here, we describe current comparative data in MGD and review the history and refinement of orthology representation in this resource.

An incomplete trafficking defect to the cell-surface leads to paradoxical thrombocytosis for human and murine MPL P106L.

PubMed

Favale, Fabrizia; Messaoudi, Kahia; Varghese, Leila N; Boukour, Siham; Pecquet, Christian; Gryshkova, Vitalina; Defour, Jean Philippe; Albu, Roxana-Irina; Bluteau, Olivier; Ballerini, Paola; Leverger, Guy; Plo, Isabelle; Debili, Najet; Raslova, Hana; Favier, Remi; Constantinescu, Stefan N; Vainchenker, William

2016-12-29

The mechanisms behind the hereditary thrombocytosis induced by the thrombopoietin (THPO) receptor MPL P106L mutant remain unknown. A complete trafficking defect to the cell surface has been reported, suggesting either weak constitutive activity or nonconventional THPO-dependent mechanisms. Here, we report that the thrombocytosis phenotype induced by MPL P106L belongs to the paradoxical group, where low MPL levels on platelets and mature megakaryocytes (MKs) lead to high serum THPO levels, whereas weak but not absent MPL cell-surface localization in earlier MK progenitors allows response to THPO by signaling and amplification of the platelet lineage. MK progenitors from patients showed no spontaneous growth and responded to THPO, and MKs expressed MPL on their cell surface at low levels, whereas their platelets did not respond to THPO. Transduction of MPL P106L in CD34 + cells showed that this receptor was more efficiently localized at the cell surface on immature than on mature MKs, explaining a proliferative response to THPO of immature cells and a defect in THPO clearance in mature cells. In a retroviral mouse model performed in Mpl -/- mice, MPL P106L could induce a thrombocytosis phenotype with high circulating THPO levels. Furthermore, we could select THPO-dependent cell lines with more cell-surface MPL P106L localization that was detected by flow cytometry and [ 125 I]-THPO binding. Altogether, these results demonstrate that MPL P106L is a receptor with an incomplete defect in trafficking, which induces a low but not absent localization of the receptor on cell surface and a response to THPO in immature MK cells. © 2016 by The American Society of Hematology.

Language model: Extension to solve inconsistency, incompleteness, and short query in cultural heritage collection

NASA Astrophysics Data System (ADS)

Tan, Kian Lam; Lim, Chen Kim

2017-10-01

With the explosive growth of online information such as email messages, news articles, and scientific literature, many institutions and museums are converting their cultural collections from physical data to digital format. However, this conversion resulted in the issues of inconsistency and incompleteness. Besides, the usage of inaccurate keywords also resulted in short query problem. Most of the time, the inconsistency and incompleteness are caused by the aggregation fault in annotating a document itself while the short query problem is caused by naive user who has prior knowledge and experience in cultural heritage domain. In this paper, we presented an approach to solve the problem of inconsistency, incompleteness and short query by incorporating the Term Similarity Matrix into the Language Model. Our approach is tested on the Cultural Heritage in CLEF (CHiC) collection which consists of short queries and documents. The results show that the proposed approach is effective and has improved the accuracy in retrieval time.

Genetically Engineered Mouse Models for Studying Inflammatory Bowel Disease

PubMed Central

Mizoguchi, Atsushi; Takeuchi, Takahito; Himuro, Hidetomo; Okada, Toshiyuki; Mizoguchi, Emiko

2015-01-01

Inflammatory bowel disease (IBD) is a chronic intestinal inflammatory condition that is mediated by very complex mechanisms controlled by genetic, immune, and environmental factors. More than 74 kinds of genetically engineered mouse strains have been established since 1993 for studying IBD. Although mouse models cannot fully reflect human IBD, they have provided significant contributions for not only understanding the mechanism, but also developing new therapeutic means for IBD. Indeed, 20 kinds of genetically engineered mouse models carry the susceptibility genes identified in human IBD, and the functions of some other IBD susceptibility genes have also been dissected out using mouse models. Cutting-edge technologies such as cell-specific and inducible knockout systems, which were recently employed to mouse IBD models, have further enhanced the ability of investigators to provide important and unexpected rationales for developing new therapeutic strategies for IBD. In this review article, we briefly introduce 74 kinds of genetically engineered mouse models that spontaneously develop intestinal inflammation. PMID:26387641

Egg yolk antibodies for detection and neutralization of Clostridium botulinum type A neurotoxin.

PubMed

Trott, D L; Yang, M; Gonzalez, J; Larson, A E; Tepp, W H; Johnson, E A; Cook, M E

2009-05-01

The objective of this research project was to determine the usefulness of an egg antibody platform for producing materials for the detection and neutralization of botulinum type A neurotoxin. Yield estimates for detection and neutralizing antibodies produced using methods described were calculated. Antibody specific to botulinum toxoid A (aToxoid) and toxin A (aBoNT/A) was produced by immunizing hens with botulinum toxoid A (toxoid) followed by increasing amounts of botulinum neurotoxin A (BoNT/A) in Freund incomplete adjuvant. Egg yolks were extracted with polyethylene glycol (PEG) for antibody detection and neutralization experiments. A model aToxoid/toxoid immunoassay using only egg yolk antibody was developed and had a detection limit of 1 pg/ml of toxoid. In an indirect enzyme-linked immunosorbent assay of BoNT/A-specific antibody, the aBoNT/A contained more BoNT/A-specific antibody than did the aToxoid, and aBoNT/A was as effective as commercial rabbit antibody. The aToxoid provided no protection against BoNT/A in a standard mouse neutralization assay; however, 1 mg of PEG-extracted aBoNT/A neutralized 4,000 lethal doses of BoNT/A injected intraperitoneally. Based on these results, we calculated that in 1 month one hen could produce more than 100 liters of antibody detection reagents or enough antibody to neutralize approximately 11.6 million mouse lethal doses of botulinum toxin. Utilization of an egg antibody platform is potentially rapid (28 to 70 days) and scalable to kilogram quantities using current egg production facilities with as few as 1,000 hens.

Compensatory molecular and functional mechanisms in nervous system of the Grm1(crv4) mouse lacking the mGlu1 receptor: a model for motor coordination deficits.

PubMed

Rossi, Pia Irene Anna; Musante, Ilaria; Summa, Maria; Pittaluga, Anna; Emionite, Laura; Ikehata, Masami; Rastaldi, Maria Pia; Ravazzolo, Roberto; Puliti, Aldamaria

2013-09-01

The metabotropic glutamate type 1 (mGlu1) and type 5 (mGlu5) receptors, the only members of group I mGlu receptors, are implicated in synaptic plasticity and mechanisms of feedback control of glutamate release. They exhibit nearly complementary distributions throughout the central nervous system, well evident in the cerebellum, where mGlu1 receptor is most intensely expressed while mGlu5 receptor is not. Despite their different distribution, they show a similar subcellular localization and use common transducing pathways. We recently described the Grm1(crv4) mouse with motor coordination deficits and renal anomalies caused by a spontaneous mutation inactivating the mGlu1 receptor. To define the neuropathological mechanisms in these mice, we evaluated expression and function of the mGlu5 receptor in cerebral and cerebellar cortices. Western blot and immunofluorescence analyses showed mGlu5 receptor overexpression. Quantitative reverse transcriptase-polymerase chain reaction results indicated that the up-regulation is already evident at RNA level. Functional studies confirmed an enhanced glutamate release from cortical cerebral and cerebellar synaptosomes when compared with wild-type that is abolished by the mGlu5 receptor-specific inhibitor, 2-methyl-6-(phenylethynyl) pyridine hydrochloride (MPEP). Finally, acute MPEP treatment of Grm1(crv4/crv4) mice induced an evident although incomplete improvement of motor coordination, suggesting that mGlu5 receptors enhanced activity worsens, instead of improving, the motor-coordination defects in the Grm1(crv4/crv4) mice.

Arap1 Deficiency Causes Photoreceptor Degeneration in Mice.

PubMed

Moshiri, Ala; Humpal, Devin; Leonard, Brian C; Imai, Denise M; Tham, Addy; Bower, Lynette; Clary, Dave; Glaser, Thomas M; Lloyd, K C Kent; Murphy, Christopher J

2017-03-01

Small guanosine triphosphatase (GTPase) ADP-ribosylation factors (Arfs) regulate membrane traffic and actin reorganization under the control of GTPase-activating proteins (GAPs). Arap1 is an Arf-directed GAP that inhibits the trafficking of epidermal growth factor receptor (EGFR) to the early endosome, but the diversity of its functions is incompletely understood. The aim of this study was to determine the role of Arap1 in the mammalian retina. Genetically engineered Arap1 knockout mice were screened for ocular abnormalities in the National Institutes of Health Knockout Mouse Production and Phenotyping (KOMP2) Project. Arap1 knockout and wild-type eyes were imaged using optical coherence tomography and fundus photography, and analyzed by immunohistochemistry. Arap1-/- mice develop a normal appearing retina, but undergo photoreceptor degeneration starting at 4 weeks postnatal age. The fundus appearance of mutants is notable for pigmentary changes, optic nerve pallor, vascular attenuation, and outer retinal thinning, reminiscent of retinitis pigmentosa in humans. Immunohistochemical studies suggest the cell death is predominantly in the outer nuclear layer. Functional evaluation of the retina by electroretinography reveals amplitudes are reduced. Arap1 is detected most notably in Müller glia, and not in photoreceptors, implicating a role for Müller glia in photoreceptor survival. Arap1 is necessary for normal photoreceptor survival in mice, and may be a novel gene relevant to human retinal degenerative processes, although its mechanism is unknown. Further studies in this mouse model of retinal degeneration will give insights into the cellular functions and signaling pathways in which Arap1 participates.

Feasibility of Whole-Body Functional Mouse Imaging Using Helical Pinhole SPECT

PubMed Central

Metzler, Scott D.; Vemulapalli, Sreekanth; Jaszczak, Ronald J.; Akabani, Gamal; Chin, Bennett B.

2010-01-01

Purpose Detailed in vivo whole-body biodistributions of radiolabeled tracers may characterize the longitudinal progression of disease, and changes with therapeutic interventions. Small-animal imaging in mice is particularly attractive due to the wide array of well characterized genetically and surgically created models of disease. Single Photon Emission Computed Tomography (SPECT) imaging using pinhole collimation provides high resolution and sensitivity, but conventional methods using circular acquisitions result in severe image truncation and incomplete sampling of data which prevent the accurate determination of whole-body radiotracer biodistributions. This study describes the feasibility of helical acquisition paths to mitigate these effects. Procedures Helical paths of pinhole apertures were implemented using an external robotic stage aligned with the axis of rotation (AOR) of the scanner. Phantom and mouse scans were performed using helical paths and either circular or bi-circular orbits at the same radius of rotation (ROR). The bi-circular orbits consisted of two 360-degree scans separated by an axial shift to increase the axial field of view (FOV) and to improve the complete-sampling properties. Results Reconstructions of phantoms and mice acquired with helical paths show good image quality and are visually free of both truncation and axial-blurring artifacts. Circular orbits yielded reconstructions with both artifacts and a limited effective FOV. The bi-circular scans enlarged the axial FOV, but still suffered from truncation and sampling artifacts. Conclusions Helical paths can provide complete sampling data and large effective FOV, yielding 3D full-body in vivo biodistributions while still maintaining a small distance from the aperture to the object for good sensitivity and resolution. PMID:19521736

Three‐dimensional myocardial scarring along myofibers after coronary ischemia–reperfusion revealed by computerized images of histological assays

PubMed Central

Katz, Monica Y.; Kusakari, Yoichiro; Aoyagi, Hiroko; Higa, Jason K.; Xiao, Chun‐Yang; Abdelkarim, Ahmed Z.; Marh, Karra; Aoyagi, Toshinori; Rosenzweig, Anthony; Lozanoff, Scott; Matsui, Takashi

2014-01-01

Abstract Adverse left ventricular (LV) remodeling after acute myocardial infarction is characterized by LV dilatation and development of a fibrotic scar, and is a critical factor for the prognosis of subsequent development of heart failure. Although myofiber organization is recognized as being important for preserving physiological cardiac function and structure, the anatomical features of injured myofibers during LV remodeling have not been fully defined. In a mouse model of ischemia–reperfusion (I/R) injury induced by left anterior descending coronary artery ligation, our previous histological assays demonstrated that broad fibrotic scarring extended from the initial infarct zone to the remote zone, and was clearly demarcated along midcircumferential myofibers. Additionally, no fibrosis was observed in longitudinal myofibers in the subendocardium and subepicardium. However, a histological analysis of tissue sections does not adequately indicate myofiber injury distribution throughout the entire heart. To address this, we investigated patterns of scar formation along myofibers using three‐dimensional (3D) images obtained from multiple tissue sections from mouse hearts subjected to I/R injury. The fibrotic scar area observed in the 3D images was consistent with the distribution of the midcircumferential myofibers. At the apex, the scar formation tracked along the myofibers in an incomplete C‐shaped ring that converged to a triangular shape toward the end. Our findings suggest that myocyte injury after transient coronary ligation extends along myofibers, rather than following the path of coronary arteries penetrating the myocardium. The injury pattern observed along myofibers after I/R injury could be used to predict prognoses for patients with myocardial infarction. PMID:25347856

40 CFR 86.085-20 - Incomplete vehicles, classification.

Code of Federal Regulations, 2013 CFR

2013-07-01

... 40 Protection of Environment 19 2013-07-01 2013-07-01 false Incomplete vehicles, classification... PROGRAMS (CONTINUED) CONTROL OF EMISSIONS FROM NEW AND IN-USE HIGHWAY VEHICLES AND ENGINES General Provisions for Emission Regulations for 1977 and Later Model Year New Light-Duty Vehicles, Light-Duty Trucks...

40 CFR 86.085-20 - Incomplete vehicles, classification.

Code of Federal Regulations, 2014 CFR

2014-07-01

... 40 Protection of Environment 19 2014-07-01 2014-07-01 false Incomplete vehicles, classification... PROGRAMS (CONTINUED) CONTROL OF EMISSIONS FROM NEW AND IN-USE HIGHWAY VEHICLES AND ENGINES General Provisions for Emission Regulations for 1977 and Later Model Year New Light-Duty Vehicles, Light-Duty Trucks...

Mutations in HYAL2, Encoding Hyaluronidase 2, Cause a Syndrome of Orofacial Clefting and Cor Triatriatum Sinister in Humans and Mice

PubMed Central

Hasan, S. Naimul; Mark, Brian; Harlalka, Gaurav V.; Patton, Michael A.; Ishida, Miho; Sharma, Sanjay; Faqeih, Eissa; Blakley, Brian; Jackson, Mike; Lees, Melissa; Dolinsky, Vernon; Cross, Leroy; Stanier, Philip; Salter, Claire; Baple, Emma L.; Crosby, Andrew H.

2017-01-01

Orofacial clefting is amongst the most common of birth defects, with both genetic and environmental components. Although numerous studies have been undertaken to investigate the complexities of the genetic etiology of this heterogeneous condition, this factor remains incompletely understood. Here, we describe mutations in the HYAL2 gene as a cause of syndromic orofacial clefting. HYAL2, encoding hyaluronidase 2, degrades extracellular hyaluronan, a critical component of the developing heart and palatal shelf matrix. Transfection assays demonstrated that the gene mutations destabilize the molecule, dramatically reducing HYAL2 protein levels. Consistent with the clinical presentation in affected individuals, investigations of Hyal2-/- mice revealed craniofacial abnormalities, including submucosal cleft palate. In addition, cor triatriatum sinister and hearing loss, identified in a proportion of Hyal2-/- mice, were also found as incompletely penetrant features in affected humans. Taken together our findings identify a new genetic cause of orofacial clefting in humans and mice, and define the first molecular cause of human cor triatriatum sinister, illustrating the fundamental importance of HYAL2 and hyaluronan turnover for normal human and mouse development. PMID:28081210

Nanoparticulate carbon black in cigarette smoke induces DNA cleavage and Th17-mediated emphysema

PubMed Central

You, Ran; Lu, Wen; Shan, Ming; Berlin, Jacob M; Samuel, Errol LG; Marcano, Daniela C; Sun, Zhengzong; Sikkema, William KA; Yuan, Xiaoyi; Song, Lizhen; Hendrix, Amanda Y; Tour, James M; Corry, David B; Kheradmand, Farrah

2015-01-01

Chronic inhalation of cigarette smoke is the major cause of sterile inflammation and pulmonary emphysema. The effect of carbon black (CB), a universal constituent of smoke derived from the incomplete combustion of organic material, in smokers and non-smokers is less known. In this study, we show that insoluble nanoparticulate carbon black (nCB) accumulates in human myeloid dendritic cells (mDCs) from emphysematous lung and in CD11c+ lung antigen presenting cells (APC) of mice exposed to smoke. Likewise, nCB intranasal administration induced emphysema in mouse lungs. Delivered by smoking or intranasally, nCB persisted indefinitely in mouse lung, activated lung APCs, and promoted T helper 17 cell differentiation through double-stranded DNA break (DSB) and ASC-mediated inflammasome assembly in phagocytes. Increasing the polarity or size of CB mitigated many adverse effects. Thus, nCB causes sterile inflammation, DSB, and emphysema and explains adverse health outcomes seen in smokers while implicating the dangers of nCB exposure in non-smokers. DOI: http://dx.doi.org/10.7554/eLife.09623.001 PMID:26437452

Genome-wide expression profiling of five mouse models identifies similarities and differences with human psoriasis.

PubMed

Swindell, William R; Johnston, Andrew; Carbajal, Steve; Han, Gangwen; Wohn, Christian; Lu, Jun; Xing, Xianying; Nair, Rajan P; Voorhees, John J; Elder, James T; Wang, Xiao-Jing; Sano, Shigetoshi; Prens, Errol P; DiGiovanni, John; Pittelkow, Mark R; Ward, Nicole L; Gudjonsson, Johann E

2011-04-04

Development of a suitable mouse model would facilitate the investigation of pathomechanisms underlying human psoriasis and would also assist in development of therapeutic treatments. However, while many psoriasis mouse models have been proposed, no single model recapitulates all features of the human disease, and standardized validation criteria for psoriasis mouse models have not been widely applied. In this study, whole-genome transcriptional profiling is used to compare gene expression patterns manifested by human psoriatic skin lesions with those that occur in five psoriasis mouse models (K5-Tie2, imiquimod, K14-AREG, K5-Stat3C and K5-TGFbeta1). While the cutaneous gene expression profiles associated with each mouse phenotype exhibited statistically significant similarity to the expression profile of psoriasis in humans, each model displayed distinctive sets of similarities and differences in comparison to human psoriasis. For all five models, correspondence to the human disease was strong with respect to genes involved in epidermal development and keratinization. Immune and inflammation-associated gene expression, in contrast, was more variable between models as compared to the human disease. These findings support the value of all five models as research tools, each with identifiable areas of convergence to and divergence from the human disease. Additionally, the approach used in this paper provides an objective and quantitative method for evaluation of proposed mouse models of psoriasis, which can be strategically applied in future studies to score strengths of mouse phenotypes relative to specific aspects of human psoriasis.

NOGGIN IS REQUIRED FOR NORMAL LOBE PATTERNING AND DUCTAL BUDDING IN THE MOUSE PROSTATE

PubMed Central

Cook, Crist; Vezina, Chad M.; Hicks, Sarah M.; Shaw, Aubie; Yu, Min; Peterson, Richard E.; Bushman, Wade

2008-01-01

Mesenchymal expression of the BMP antagonist NOGGIN during prostate development plays a critical role in pre-natal ventral prostate development and opposes BMP4-mediated inhibition of cell proliferation during postnatal ductal development. Morphologic examination of newborn Noggin-/- male fetuses revealed genitourinary anomalies including cryptorchidism, incomplete separation of the hindgut from the urogenital sinus (UGS), absence of the ventral mesenchymal pad and a complete loss of ventral prostate (VP) budding. Examination of lobe-specific marker expression in the E14 Noggin-/- UGS rescued by transplantation under the renal capsule of a male nude mouse confirmed a complete loss of VP determination. More modest effects were observed in the other lobes, including decreased number of ductal buds in the dorsal and lateral prostates of newborn Noggin-/- males. BMP4 and BMP7 have been shown to inhibit ductal budding and outgrowth by negatively regulating epithelial cell proliferation. We show here that NOGGIN can neutralize budding inhibition by BMP4 and rescues branching morphogenesis of BMP4-exposed UGS in organ culture and show that the effects of BMP4 and NOGGIN activities converge on P63+ epithelial cells located at nascent duct tips. Together, these studies show that the BMP-NOGGIN axis regulates patterning of the ventral prostate, regulates ductal budding, and controls proliferation of P63+ epithelial cells in the nascent ducts of developing mouse prostate. PMID:18028901

Identifying novel genetic determinants of hemostatic balance.

PubMed

Ginsburg, D

2005-08-01

Incomplete penetrance and variable expressivity confound the diagnosis and therapy of most inherited thrombotic and hemorrhagic disorders. For many of these diseases, some or most of this variability is determined by genetic modifiers distinct from the primary disease gene itself. Clues toward identifying such modifier genes may come from studying rare Mendelian disorders of hemostasis. Examples include identification of the cause of combined factor V and VIII deficiency as mutations in the ER Golgi intermediate compartment proteins LMAN1 and MCFD2. These proteins form a cargo receptor that facilitates the transport of factors V and VIII, and presumably other proteins, from the ER to the Golgi. A similar positional cloning approach identified ADAMTS-13 as the gene responsible for familial TTP. Along with the work of many other groups, these findings identified VWF proteolysis by ADAMTS-13 as a key regulatory pathway for hemostasis. Recent advances in mouse genetics also provide powerful tools for the identification of novel genes contributing to hemostatic balance. Genetic studies of inbred mouse lines with unusually high and unusually low plasma VWF levels identified polymorphic variation in the expression of a glycosyltransferase gene, Galgt2, as an important determinant of plasma VWF levels in the mouse. Ongoing studies in mice genetically engineered to carry the factor V Leiden mutation may similarly identify novel genes contributing to thrombosis risk in humans.

Behavioral metabolomics analysis identifies novel neurochemical signatures in methamphetamine sensitization

PubMed Central

Adkins, Daniel E.; McClay, Joseph L.; Vunck, Sarah A.; Batman, Angela M.; Vann, Robert E.; Clark, Shaunna L.; Souza, Renan P.; Crowley, James J.; Sullivan, Patrick F.; van den Oord, Edwin J.C.G.; Beardsley, Patrick M.

2014-01-01

Behavioral sensitization has been widely studied in animal models and is theorized to reflect neural modifications associated with human psychostimulant addiction. While the mesolimbic dopaminergic pathway is known to play a role, the neurochemical mechanisms underlying behavioral sensitization remain incompletely understood. In the present study, we conducted the first metabolomics analysis to globally characterize neurochemical differences associated with behavioral sensitization. Methamphetamine-induced sensitization measures were generated by statistically modeling longitudinal activity data for eight inbred strains of mice. Subsequent to behavioral testing, nontargeted liquid and gas chromatography-mass spectrometry profiling was performed on 48 brain samples, yielding 301 metabolite levels per sample after quality control. Association testing between metabolite levels and three primary dimensions of behavioral sensitization (total distance, stereotypy and margin time) showed four robust, significant associations at a stringent metabolome-wide significance threshold (false discovery rate < 0.05). Results implicated homocarnosine, a dipeptide of GABA and histidine, in total distance sensitization, GABA metabolite 4-guanidinobutanoate and pantothenate in stereotypy sensitization, and myo-inositol in margin time sensitization. Secondary analyses indicated that these associations were independent of concurrent methamphetamine levels and, with the exception of the myo-inositol association, suggest a mechanism whereby strain-based genetic variation produces specific baseline neurochemical differences that substantially influence the magnitude of MA-induced sensitization. These findings demonstrate the utility of mouse metabolomics for identifying novel biomarkers, and developing more comprehensive neurochemical models, of psychostimulant sensitization. PMID:24034544

Deep vein thrombus formation induced by flow reduction in mice is determined by venous side branches.

PubMed

Brandt, Moritz; Schönfelder, Tanja; Schwenk, Melanie; Becker, Christian; Jäckel, Sven; Reinhardt, Christoph; Stark, Konstantin; Massberg, Steffen; Münzel, Thomas; von Brühl, Marie-Luise; Wenzel, Philip

2014-01-01

Interaction between vascular wall abnormalities, inflammatory leukocytes, platelets, coagulation factors and hemorheology in the pathogenesis of deep vein thrombosis (DVT) is incompletely understood, requiring well defined animal models of human disease. We subjected male C57BL/6 mice to ligation of the inferior vena cava (IVC) as a flow reduction model to induce DVT. Thrombus size and weight were analyzed macroscopically and sonographically by B-mode, pulse wave (pw) Doppler and power Doppler imaging (PDI) using high frequency ultrasound. Thrombus size varied substantially between individual procedures and mice, irrespective of the flow reduction achieved by the ligature. Interestingly, PDI accurately predicted thrombus size in a very robust fashion (r2 = 0.9734, p < 0.0001). Distance of the insertion of side branches from the ligature significantly determines thrombus weight (r2 = 0.5597, p < 0.0001) and length (r2 = 0.5441, p < 0.0001) in the IVC, regardless of the flow measured by pw-Doppler with distances <1.5 mm drastically impairing thrombus formation. Occlusion of side branches prior to ligation of IVC did not increase thrombus size, probably due to patent side branches inaccessible to surgery. Venous side branches influence thrombus size in experimental DVT and might therefore prevent thrombus formation. This renders vessel anatomy and hemorheology important determinants in mouse models of DVT, which should be controlled for.

Low-energy fusion dynamics of weakly bound nuclei: A time dependent perspective

NASA Astrophysics Data System (ADS)

Diaz-Torres, A.; Boselli, M.

2016-05-01

Recent dynamical fusion models for weakly bound nuclei at low incident energies, based on a time-dependent perspective, are briefly presented. The main features of both the PLATYPUS model and a new quantum approach are highlighted. In contrast to existing timedependent quantum models, the present quantum approach separates the complete and incomplete fusion from the total fusion. Calculations performed within a toy model for 6Li + 209Bi at near-barrier energies show that converged excitation functions for total, complete and incomplete fusion can be determined with the time-dependent wavepacket dynamics.

Optimizing mouse models of neurodegenerative disorders: are therapeutics in sight?

PubMed

Lutz, Cathleen M; Osborne, Melissa A

2013-01-01

The genomic and biologic conservation between mice and humans, along with our increasing ability to manipulate the mouse genome, places the mouse as a premier model for deciphering disease mechanisms and testing potential new therapies. Despite these advantages, mouse models of neurodegenerative disease are sometimes difficult to generate and can present challenges that must be carefully addressed when used for preclinical studies. For those models that do exist, the standardization and optimization of the models is a critical step in ensuring success in both basic research and preclinical use. This review looks back on the history of model development for neurodegenerative diseases and highlights the key strategies that have been learned in order to improve the design, development and use of mouse models in the study of neurodegenerative disease.

Applications and Limitations of Mouse Models for Understanding Human Atherosclerosis

PubMed Central

von Scheidt, Moritz; Zhao, Yuqi; Kurt, Zeyneb; Pan, Calvin; Zeng, Lingyao; Yang, Xia; Schunkert, Heribert; Lusis, Aldons J.

2017-01-01

Most of the biological understanding of mechanisms underlying coronary artery disease (CAD) derives from studies of mouse models. The identification of multiple CAD loci and strong candidate genes in large human genome-wide association studies (GWAS) presented an opportunity to examine the relevance of mouse models for the human disease. We comprehensively reviewed the mouse literature, including 827 literature-derived genes, and compared it to human data. First, we observed striking concordance of risk factors for atherosclerosis in mice and humans. Second, there was highly significant overlap of mouse genes with human genes identified by GWAS. In particular, of the 46 genes with strong association signals in CAD-GWAS that were studied in mouse models all but one exhibited consistent effects on atherosclerosis-related phenotypes. Third, we compared 178 CAD-associated pathways derived from human GWAS with 263 from mouse studies and observed that over 50% were consistent between both species. PMID:27916529

Genetically engineered mouse models for studying inflammatory bowel disease.

PubMed

Mizoguchi, Atsushi; Takeuchi, Takahito; Himuro, Hidetomo; Okada, Toshiyuki; Mizoguchi, Emiko

2016-01-01

Inflammatory bowel disease (IBD) is a chronic intestinal inflammatory condition that is mediated by very complex mechanisms controlled by genetic, immune, and environmental factors. More than 74 kinds of genetically engineered mouse strains have been established since 1993 for studying IBD. Although mouse models cannot fully reflect human IBD, they have provided significant contributions for not only understanding the mechanism, but also developing new therapeutic means for IBD. Indeed, 20 kinds of genetically engineered mouse models carry the susceptibility genes identified in human IBD, and the functions of some other IBD susceptibility genes have also been dissected out using mouse models. Cutting-edge technologies such as cell-specific and inducible knockout systems, which were recently employed to mouse IBD models, have further enhanced the ability of investigators to provide important and unexpected rationales for developing new therapeutic strategies for IBD. In this review article, we briefly introduce 74 kinds of genetically engineered mouse models that spontaneously develop intestinal inflammation. Copyright © 2015 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.

Mouse Tumor Biology (MTB): a database of mouse models for human cancer.

PubMed

Bult, Carol J; Krupke, Debra M; Begley, Dale A; Richardson, Joel E; Neuhauser, Steven B; Sundberg, John P; Eppig, Janan T

2015-01-01

The Mouse Tumor Biology (MTB; http://tumor.informatics.jax.org) database is a unique online compendium of mouse models for human cancer. MTB provides online access to expertly curated information on diverse mouse models for human cancer and interfaces for searching and visualizing data associated with these models. The information in MTB is designed to facilitate the selection of strains for cancer research and is a platform for mining data on tumor development and patterns of metastases. MTB curators acquire data through manual curation of peer-reviewed scientific literature and from direct submissions by researchers. Data in MTB are also obtained from other bioinformatics resources including PathBase, the Gene Expression Omnibus and ArrayExpress. Recent enhancements to MTB improve the association between mouse models and human genes commonly mutated in a variety of cancers as identified in large-scale cancer genomics studies, provide new interfaces for exploring regions of the mouse genome associated with cancer phenotypes and incorporate data and information related to Patient-Derived Xenograft models of human cancers. © The Author(s) 2014. Published by Oxford University Press on behalf of Nucleic Acids Research.

Graph Embedding Techniques for Bounding Condition Numbers of Incomplete Factor Preconditioning

NASA Technical Reports Server (NTRS)

Guattery, Stephen

1997-01-01

We extend graph embedding techniques for bounding the spectral condition number of preconditioned systems involving symmetric, irreducibly diagonally dominant M-matrices to systems where the preconditioner is not diagonally dominant. In particular, this allows us to bound the spectral condition number when the preconditioner is based on an incomplete factorization. We provide a review of previous techniques, describe our extension, and give examples both of a bound for a model problem, and of ways in which our techniques give intuitive way of looking at incomplete factor preconditioners.

The latest animal models of ovarian cancer for novel drug discovery.

PubMed

Magnotti, Elizabeth; Marasco, Wayne A

2018-03-01

Epithelial ovarian cancer is a heterogeneous disease classified into five subtypes, each with a different molecular profile. Most cases of ovarian cancer are diagnosed after metastasis of the primary tumor and are resistant to traditional platinum-based chemotherapeutics. Mouse models of ovarian cancer have been utilized to discern ovarian cancer tumorigenesis and the tumor's response to therapeutics. Areas covered: The authors provide a review of mouse models currently employed to understand ovarian cancer. This article focuses on advances in the development of orthotopic and patient-derived tumor xenograft (PDX) mouse models of ovarian cancer and discusses current humanized mouse models of ovarian cancer. Expert opinion: The authors suggest that humanized mouse models of ovarian cancer will provide new insight into the role of the human immune system in combating and augmenting ovarian cancer and aid in the development of novel therapeutics. Development of humanized mouse models will take advantage of the NSG and NSG-SGM3 strains of mice as well as new strains that are actively being derived.

How Genetically Engineered Mouse Tumor Models Provide Insights Into Human Cancers

PubMed Central

Politi, Katerina; Pao, William

2011-01-01

Genetically engineered mouse models (GEMMs) of human cancer were first created nearly 30 years ago. These early transgenic models demonstrated that mouse cells could be transformed in vivo by expression of an oncogene. A new field emerged, dedicated to generating and using mouse models of human cancer to address a wide variety of questions in cancer biology. The aim of this review is to highlight the contributions of mouse models to the diagnosis and treatment of human cancers. Because of the breadth of the topic, we have selected representative examples of how GEMMs are clinically relevant rather than provided an exhaustive list of experiments. Today, as detailed here, sophisticated mouse models are being created to study many aspects of cancer biology, including but not limited to mechanisms of sensitivity and resistance to drug treatment, oncogene cooperation, early detection, and metastasis. Alternatives to GEMMs, such as chemically induced or spontaneous tumor models, are not discussed in this review. PMID:21263096

Integrating model behavior, optimization, and sensitivity/uncertainty analysis: overview and application of the MOUSE software toolbox

USDA-ARS?s Scientific Manuscript database

This paper provides an overview of the Model Optimization, Uncertainty, and SEnsitivity Analysis (MOUSE) software application, an open-source, Java-based toolbox of visual and numerical analysis components for the evaluation of environmental models. MOUSE is based on the OPTAS model calibration syst...

Quantitative assessment of computational models for retinotopic map formation

PubMed Central

Sterratt, David C; Cutts, Catherine S; Willshaw, David J; Eglen, Stephen J

2014-01-01

ABSTRACT Molecular and activity‐based cues acting together are thought to guide retinal axons to their terminal sites in vertebrate optic tectum or superior colliculus (SC) to form an ordered map of connections. The details of mechanisms involved, and the degree to which they might interact, are still not well understood. We have developed a framework within which existing computational models can be assessed in an unbiased and quantitative manner against a set of experimental data curated from the mouse retinocollicular system. Our framework facilitates comparison between models, testing new models against known phenotypes and simulating new phenotypes in existing models. We have used this framework to assess four representative models that combine Eph/ephrin gradients and/or activity‐based mechanisms and competition. Two of the models were updated from their original form to fit into our framework. The models were tested against five different phenotypes: wild type, Isl2‐EphA3 ki/ki, Isl2‐EphA3 ki/+, ephrin‐A2,A3,A5 triple knock‐out (TKO), and Math5 −/− (Atoh7). Two models successfully reproduced the extent of the Math5 −/− anteromedial projection, but only one of those could account for the collapse point in Isl2‐EphA3 ki/+. The models needed a weak anteroposterior gradient in the SC to reproduce the residual order in the ephrin‐A2,A3,A5 TKO phenotype, suggesting either an incomplete knock‐out or the presence of another guidance molecule. Our article demonstrates the importance of testing retinotopic models against as full a range of phenotypes as possible, and we have made available MATLAB software, we wrote to facilitate this process. © 2014 Wiley Periodicals, Inc. Develop Neurobiol 75: 641–666, 2015 PMID:25367067

Disrupting the male germ line to find infertility and contraception targets.

PubMed

Archambeault, Denise R; Matzuk, Martin M

2014-05-01

Genetically-manipulated mouse models have become indispensible for broadening our understanding of genes and pathways related to male germ cell development. Until suitable in vitro systems for studying spermatogenesis are perfected, in vivo models will remain the gold standard for inquiry into testicular function. Here, we discuss exciting advances that are allowing researchers faster, easier, and more customizable access to their mouse models of interest. Specifically, the trans-NIH Knockout Mouse Project (KOMP) is working to generate knockout mouse models of every gene in the mouse genome. The related Knockout Mouse Phenotyping Program (KOMP2) is performing systematic phenotypic analysis of this genome-wide collection of knockout mice, including fertility screening. Together, these programs will not only uncover new genes involved in male germ cell development but also provide the research community with the mouse models necessary for further investigations. In addition to KOMP/KOMP2, another promising development in the field of mouse models is the advent of CRISPR (clustered regularly interspaced short palindromic repeat)-Cas technology. Utilizing 20 nucleotide guide sequences, CRISPR/Cas has the potential to introduce sequence-specific insertions, deletions, and point mutations to produce null, conditional, activated, or reporter-tagged alleles. CRISPR/Cas can also successfully target multiple genes in a single experimental step, forgoing the multiple generations of breeding traditionally required to produce mouse models with deletions, insertions, or mutations in multiple genes. In addition, CRISPR/Cas can be used to create mouse models carrying variants identical to those identified in infertile human patients, providing the opportunity to explore the effects of such mutations in an in vivo system. Both the KOMP/KOMP2 projects and the CRISPR/Cas system provide powerful, accessible genetic approaches to the study of male germ cell development in the mouse. A more complete understanding of male germ cell biology is critical for the identification of novel targets for potential non-hormonal contraceptive intervention. Copyright © 2014. Published by Elsevier Masson SAS.

Genome-Wide Expression Profiling of Five Mouse Models Identifies Similarities and Differences with Human Psoriasis

PubMed Central

Swindell, William R.; Johnston, Andrew; Carbajal, Steve; Han, Gangwen; Wohn, Christian; Lu, Jun; Xing, Xianying; Nair, Rajan P.; Voorhees, John J.; Elder, James T.; Wang, Xiao-Jing; Sano, Shigetoshi; Prens, Errol P.; DiGiovanni, John; Pittelkow, Mark R.; Ward, Nicole L.; Gudjonsson, Johann E.

2011-01-01

Development of a suitable mouse model would facilitate the investigation of pathomechanisms underlying human psoriasis and would also assist in development of therapeutic treatments. However, while many psoriasis mouse models have been proposed, no single model recapitulates all features of the human disease, and standardized validation criteria for psoriasis mouse models have not been widely applied. In this study, whole-genome transcriptional profiling is used to compare gene expression patterns manifested by human psoriatic skin lesions with those that occur in five psoriasis mouse models (K5-Tie2, imiquimod, K14-AREG, K5-Stat3C and K5-TGFbeta1). While the cutaneous gene expression profiles associated with each mouse phenotype exhibited statistically significant similarity to the expression profile of psoriasis in humans, each model displayed distinctive sets of similarities and differences in comparison to human psoriasis. For all five models, correspondence to the human disease was strong with respect to genes involved in epidermal development and keratinization. Immune and inflammation-associated gene expression, in contrast, was more variable between models as compared to the human disease. These findings support the value of all five models as research tools, each with identifiable areas of convergence to and divergence from the human disease. Additionally, the approach used in this paper provides an objective and quantitative method for evaluation of proposed mouse models of psoriasis, which can be strategically applied in future studies to score strengths of mouse phenotypes relative to specific aspects of human psoriasis. PMID:21483750

[Effect of topical application of a recombinant adenovirus carrying promyelocytic leukemia gene in a psoriasis-like mouse model].

PubMed

Wang, Qiongyu; Zhang, Aijun; Ma, Huiqun; Wang, Shijie; Ma, Yunyun; Zou, Xingwei; Li, Ruilian

2013-03-01

To investigate the effects of topical treatment with adenovirus-mediated promyelocytic leukemia gene (PML) gene in a psoriasis-like mouse model. The effect of adenovirus-mediated PML gene on the granular layer of mouse tail scale epidermis and epithelial mitosis were observed on longitudinal histological sections prepared from the tail skin and vaginal epithelium of the mice. Adenovirus-mediated PML gene significantly inhibited mitosis of mouse vaginal epithelial cells and promoted the formation of granular layer in mouse tail scale epidermis. The therapeutic effect of PML gene in the psoriasis-like mouse model may be associated with increased granular cells and suppressed epidemic cell proliferation.

Statistical Aspects of Point Count Sampling

Treesearch

Richard J. Barker; John R. Sauer

1995-01-01

The dominant feature of point counts is that they do not census birds, but instead provide incomplete counts of individuals present within a survey plot. Considering a simple model for point count sampling, we demonstrate that use of these incomplete counts can bias estimators and testing procedures, leading to inappropriate conclusions. A large portion of the...

Generation of transgenic mouse model using PTTG as an oncogene.

PubMed

Kakar, Sham S; Kakar, Cohin

2015-01-01

The close physiological similarity between the mouse and human has provided tools to understanding the biological function of particular genes in vivo by introduction or deletion of a gene of interest. Using a mouse as a model has provided a wealth of resources, knowledge, and technology, helping scientists to understand the biological functions, translocation, trafficking, and interaction of a candidate gene with other intracellular molecules, transcriptional regulation, posttranslational modification, and discovery of novel signaling pathways for a particular gene. Most importantly, the generation of the mouse model for a specific human disease has provided a powerful tool to understand the etiology of a disease and discovery of novel therapeutics. This chapter describes in detail the step-by-step generation of the transgenic mouse model, which can be helpful in guiding new investigators in developing successful models. For practical purposes, we will describe the generation of a mouse model using pituitary tumor transforming gene (PTTG) as the candidate gene of interest.

Nitroglycerin fails to lower blood pressure in redox-dead Cys42Ser PKG1α knock-in mouse.

PubMed

Rudyk, Olena; Prysyazhna, Oleksandra; Burgoyne, Joseph R; Eaton, Philip

2012-07-17

Although nitroglycerin has remained in clinical use since 1879, the mechanism by which it relaxes blood vessels to lower blood pressure remains incompletely understood. Nitroglycerin undergoes metabolism that generates several reaction products, including oxidants, and this bioactivation process is essential for vasodilation. Protein kinase G (PKG) mediates classic nitric oxide-dependent vasorelaxation, but the 1α isoform is also independently activated by oxidation that involves interprotein disulfide formation within this homodimeric protein complex. We hypothesized that nitroglycerin-induced vasodilation is mediated by disulfide activation of PKG1α. Treating smooth muscle cells or isolated blood vessels with nitroglycerin caused PKG1α disulfide dimerization. PKG1α disulfide formation was increased in wild-type mouse aortas by in vivo nitroglycerin treatment, but this oxidation was lost as tolerance developed. To establish whether kinase oxidation underlies nitroglycerin-induced vasodilation in vivo, we used a Cys42Ser PKG1α knock-in mouse that cannot transduce oxidant signals because it does not contain the vital redox-sensing thiol. This redox-dead knock-in mouse was substantively deficient in hypotensive response to nitroglycerin compared with wild-type littermates as measured in vivo by radiotelemetry. Resistance blood vessels from knock-ins were markedly less sensitive to nitroglycerin-induced vasodilation (EC(50)=39.2 ± 10.7 μmol/L) than wild-types (EC(50)=12.1 ± 2.9 μmol/L). Furthermore, after ≈24 hours of treatment, wild-type controls stopped vasodilating to nitroglycerin, and the vascular sensitivity to nitroglycerin was decreased, whereas this tolerance phenomenon, which routinely hampers the management of hypertensive patients, was absent in knock-ins. PKG1α disulfide formation is a significant mediator of nitroglycerin-induced vasodilation, and tolerance to nitroglycerin is associated with loss of kinase oxidation.

What Is the Predictive Value of Animal Models for Vaccine Efficacy in Humans? Reevaluating the Potential of Mouse Models for the Human Immune System.

PubMed

Jameson, Stephen C; Masopust, David

2018-04-02

Much of what we understand about immunology, including the response to vaccines, come from studies in mice because they provide many practical advantages compared with research in higher mammals and humans. Nevertheless, modalities for preventing or treating disease do not always translate from mouse to humans, which has led to increasing scrutiny of the continued merits of mouse research. Here, we summarize the pros and cons of current laboratory mouse models for immunology research and discuss whether overreliance on nonphysiological, ultra-hygienic animal husbandry approaches has limited the ultimate translation potential of mouse-derived data to humans. Alternative approaches are discussed that may extend the use of the mouse model for preclinical studies. Copyright © 2018 Cold Spring Harbor Laboratory Press; all rights reserved.

Genome Patterns of Selection and Introgression of Haplotypes in Natural Populations of the House Mouse (Mus musculus)

PubMed Central

Staubach, Fabian; Lorenc, Anna; Messer, Philipp W.; Tang, Kun; Petrov, Dmitri A.; Tautz, Diethard

2012-01-01

General parameters of selection, such as the frequency and strength of positive selection in natural populations or the role of introgression, are still insufficiently understood. The house mouse (Mus musculus) is a particularly well-suited model system to approach such questions, since it has a defined history of splits into subspecies and populations and since extensive genome information is available. We have used high-density single-nucleotide polymorphism (SNP) typing arrays to assess genomic patterns of positive selection and introgression of alleles in two natural populations of each of the subspecies M. m. domesticus and M. m. musculus. Applying different statistical procedures, we find a large number of regions subject to apparent selective sweeps, indicating frequent positive selection on rare alleles or novel mutations. Genes in the regions include well-studied imprinted loci (e.g. Plagl1/Zac1), homologues of human genes involved in adaptations (e.g. alpha-amylase genes) or in genetic diseases (e.g. Huntingtin and Parkin). Haplotype matching between the two subspecies reveals a large number of haplotypes that show patterns of introgression from specific populations of the respective other subspecies, with at least 10% of the genome being affected by partial or full introgression. Using neutral simulations for comparison, we find that the size and the fraction of introgressed haplotypes are not compatible with a pure migration or incomplete lineage sorting model. Hence, it appears that introgressed haplotypes can rise in frequency due to positive selection and thus can contribute to the adaptive genomic landscape of natural populations. Our data support the notion that natural genomes are subject to complex adaptive processes, including the introgression of haplotypes from other differentiated populations or species at a larger scale than previously assumed for animals. This implies that some of the admixture found in inbred strains of mice may also have a natural origin. PMID:22956910

Inhibition of microsomal prostaglandin E2 synthase-1 as a molecular basis for the anti-inflammatory actions of boswellic acids from frankincense

PubMed Central

Siemoneit, U; Koeberle, A; Rossi, A; Dehm, F; Verhoff, M; Reckel, S; Maier, TJ; Jauch, J; Northoff, H; Bernhard, F; Doetsch, V; Sautebin, L; Werz, O

2011-01-01

BACKGROUND AND PURPOSE Frankincense, the gum resin derived from Boswellia species, showed anti-inflammatory efficacy in animal models and in pilot clinical studies. Boswellic acids (BAs) are assumed to be responsible for these effects but their anti-inflammatory efficacy in vivo and their molecular modes of action are incompletely understood. EXPERIMENTAL APPROACH A protein fishing approach using immobilized BA and surface plasmon resonance (SPR) spectroscopy were used to reveal microsomal prostaglandin E2 synthase-1 (mPGES1) as a BA-interacting protein. Cell-free and cell-based assays were applied to confirm the functional interference of BAs with mPGES1. Carrageenan-induced mouse paw oedema and rat pleurisy models were utilized to demonstrate the efficacy of defined BAs in vivo. KEY RESULTS Human mPGES1 from A549 cells or in vitro-translated human enzyme selectively bound to BA affinity matrices and SPR spectroscopy confirmed these interactions. BAs reversibly suppressed the transformation of prostaglandin (PG)H2 to PGE2 mediated by mPGES1 (IC50 = 3–10 µM). Also, in intact A549 cells, BAs selectively inhibited PGE2 generation and, in human whole blood, β-BA reduced lipopolysaccharide-induced PGE2 biosynthesis without affecting formation of the COX-derived metabolites 6-keto PGF1α and thromboxane B2. Intraperitoneal or oral administration of β-BA (1 mg·kg−1) suppressed rat pleurisy, accompanied by impaired levels of PGE2 and β-BA (1 mg·kg−1, given i.p.) also reduced mouse paw oedema, both induced by carrageenan. CONCLUSIONS AND IMPLICATIONS Suppression of PGE2 formation by BAs via interference with mPGES1 contribute to the anti-inflammatory effectiveness of BAs and of frankincense, and may constitute a biochemical basis for their anti-inflammatory properties. PMID:20840544

The effect of zirconium doping of cerium dioxide nanoparticles on pulmonary and cardiovascular toxicity and biodistribution in mice after inhalation.

PubMed

Dekkers, Susan; Miller, Mark R; Schins, Roel P F; Römer, Isabella; Russ, Mike; Vandebriel, Rob J; Lynch, Iseult; Belinga-Desaunay, Marie-France; Valsami-Jones, Eugenia; Connell, Shea P; Smith, Ian P; Duffin, Rodger; Boere, John A F; Heusinkveld, Harm J; Albrecht, Catrin; de Jong, Wim H; Cassee, Flemming R

2017-08-01

Development and manufacture of nanomaterials is growing at an exponential rate, despite an incomplete understanding of how their physicochemical characteristics affect their potential toxicity. Redox activity has been suggested to be an important physicochemical property of nanomaterials to predict their biological activity. This study assessed the influence of redox activity by modification of cerium dioxide nanoparticles (CeO 2 NPs) via zirconium (Zr) doping on the biodistribution, pulmonary and cardiovascular effects in mice following inhalation. Healthy mice (C57BL/6 J), mice prone to cardiovascular disease (ApoE -/- , western-diet fed) and a mouse model of neurological disease (5 × FAD) were exposed via nose-only inhalation to CeO 2 NPs with varying amounts of Zr-doping (0%, 27% or 78% Zr), or clean air, over a four-week period (4 mg/m 3 for 3 h/day, 5 days/week). Effects were assessed four weeks post-exposure. In all three mouse models CeO 2 NP exposure had no major toxicological effects apart from some modest inflammatory histopathology in the lung, which was not related to the amount of Zr-doping. In ApoE -/- mice CeO 2 did not change the size of atherosclerotic plaques, but there was a trend towards increased inflammatory cell content in relation to the Zr content of the CeO 2 NPs. These findings show that subacute inhalation of CeO 2 NPs causes minimal pulmonary and cardiovascular effect four weeks post-exposure and that Zr-doping of CeO 2 NPs has limited effect on these responses. Further studies with nanomaterials with a higher inherent toxicity or a broader range of redox activities are needed to fully assess the influence of redox activity on the toxicity of nanomaterials.

Half-Life of Sulfonylureas in HNF1A and HNF4A Human MODY Patients is not Prolonged as Suggested by the Mouse Hnf1a(-/-) Model.

PubMed

Urbanova, Jana; Andel, Michal; Potockova, Jana; Klima, Josef; Macek, Jan; Ptacek, Pavel; Mat'oska, Vaclav; Kumstyrova, Tereza; Heneberg, Petr

2015-01-01

Sulfonylurea derivatives are widely used for clinical treatment of human subjects with Maturity Onset Diabetes of the Young (MODY) caused by mutations in HNF-1α or HNF-4α despite the mechanism leading to their hypersensitivity is incompletely understood. In Hnf1a(-/-) mice, serum concentrations and half-life of sulfonylurea derivatives are strongly increased. We thus hypothesized that reduced sulfonylurea derivatives clearance stands behind their therapeutic potential in human HNF1A/HNF4A MODY subjects. Single doses of 3 mg glipizide and 5 mg glibenclamide/glyburide were administered sequentially to seven HNF1A/HNF4A MODY subjects and six control individuals matched for their age, BMI and CYP2C9 genotype. Pharmacokinetic (plasma concentration levels, Cmax, tmax, t1/2, AUC) and pharmacodynamic parameters (glycemia, C-peptide and insulin plasma levels) were followed for 24 hours after drug administration. We provide the first evidence on the pharmacokinetics and pharmacodynamics of sulfonylurea derivatives in human MODY subjects. The half-life of glipizide did not change, and reached 3.8±0.7 and 3.7±1.8 h in the MODY and control subjects, respectively. The half-life of glibenclamide was increased only in some MODY subjects (t1/2 9.5±6.7 and 5.0±1.4 h, respectively). Importantly, the intra- individual responses of MODY (but control) subjects to glipizide and glibenclamide treatment were highly correlated. With regards to pharmacodynamics, we observed a differential response of control but not MODY subjects to the doses of glipizide and glibenclamide applied. We rejected the hypothesis that all human MODY-associated mutations in HNF1A / HNF4A induce changes in the pharmacokinetics of sulfonylureas in humans analogically to the Hnf1a(-/-) mouse model.

Inhibition of microsomal prostaglandin E2 synthase-1 as a molecular basis for the anti-inflammatory actions of boswellic acids from frankincense.

PubMed

Siemoneit, U; Koeberle, A; Rossi, A; Dehm, F; Verhoff, M; Reckel, S; Maier, T J; Jauch, J; Northoff, H; Bernhard, F; Doetsch, V; Sautebin, L; Werz, O

2011-01-01

Frankincense, the gum resin derived from Boswellia species, showed anti-inflammatory efficacy in animal models and in pilot clinical studies. Boswellic acids (BAs) are assumed to be responsible for these effects but their anti-inflammatory efficacy in vivo and their molecular modes of action are incompletely understood. A protein fishing approach using immobilized BA and surface plasmon resonance (SPR) spectroscopy were used to reveal microsomal prostaglandin E(2) synthase-1 (mPGES1) as a BA-interacting protein. Cell-free and cell-based assays were applied to confirm the functional interference of BAs with mPGES1. Carrageenan-induced mouse paw oedema and rat pleurisy models were utilized to demonstrate the efficacy of defined BAs in vivo. Human mPGES1 from A549 cells or in vitro-translated human enzyme selectively bound to BA affinity matrices and SPR spectroscopy confirmed these interactions. BAs reversibly suppressed the transformation of prostaglandin (PG)H(2) to PGE(2) mediated by mPGES1 (IC(50) = 3-10 µM). Also, in intact A549 cells, BAs selectively inhibited PGE(2) generation and, in human whole blood, β-BA reduced lipopolysaccharide-induced PGE(2) biosynthesis without affecting formation of the COX-derived metabolites 6-keto PGF(1α) and thromboxane B(2) . Intraperitoneal or oral administration of β-BA (1 mg·kg(-1) ) suppressed rat pleurisy, accompanied by impaired levels of PGE(2) and β-BA (1 mg·kg(-1) , given i.p.) also reduced mouse paw oedema, both induced by carrageenan. Suppression of PGE(2) formation by BAs via interference with mPGES1 contribute to the anti-inflammatory effectiveness of BAs and of frankincense, and may constitute a biochemical basis for their anti-inflammatory properties. © 2010 The Authors. British Journal of Pharmacology © 2010 The British Pharmacological Society.

Differential plasma microvesicle and brain profiles of microRNA in experimental cerebral malaria.

PubMed

Cohen, Amy; Zinger, Anna; Tiberti, Natalia; Grau, Georges E R; Combes, Valery

2018-05-11

Cerebral malaria (CM) is a fatal complication of Plasmodium infection, mostly affecting children under the age of five in the sub-Saharan African region. CM pathogenesis remains incompletely understood, although sequestered infected red blood cells, inflammatory cells aggregating in the cerebral blood vessels, and the microvesicles (MV) that they release in the circulation, have been implicated. Plasma MV numbers increase in CM patients and in the murine model, where blocking their release, genetically or pharmacologically, protects against brain pathology, suggesting a role of MV in CM neuropathogenesis. In this work, the microRNA (miRNA) cargo of MV is defined for the first time during experimental CM with the overarching hypothesis that this characterization could help understand CM pathogenesis. The change in abundance of miRNA was studied following infection of CBA mice with Plasmodium berghei ANKA strain (causing experimental CM), and Plasmodium yoelii, which causes severe malaria without cerebral complications, termed non-CM (NCM). miRNA expression was analyzed using microarrays to compare MV from healthy (NI) and CM mice, yielding several miRNA of interest. The differential expression profiles of these selected miRNA (miR-146a, miR-150, miR-193b, miR-205, miR-215, miR-467a, and miR-486) were analyzed in mouse MV, MV-free plasma, and brain tissue by quantitative reverse transcription PCR (RT-qPCR). Two miRNA-miR-146a and miR-193b-were confirmed as differentially abundant in MV from CM mice, compared with NCM and NI mice. These miRNA have been shown to play various roles in inflammation, and their dysregulation during CM may be critical for triggering the neurological syndrome via regulation of their potential downstream targets. These data suggest that, in the mouse model at least, miRNA may have a regulatory role in the pathogenesis of severe malaria.

Latent Class Analysis of Incomplete Data via an Entropy-Based Criterion

PubMed Central

Larose, Chantal; Harel, Ofer; Kordas, Katarzyna; Dey, Dipak K.

2016-01-01

Latent class analysis is used to group categorical data into classes via a probability model. Model selection criteria then judge how well the model fits the data. When addressing incomplete data, the current methodology restricts the imputation to a single, pre-specified number of classes. We seek to develop an entropy-based model selection criterion that does not restrict the imputation to one number of clusters. Simulations show the new criterion performing well against the current standards of AIC and BIC, while a family studies application demonstrates how the criterion provides more detailed and useful results than AIC and BIC. PMID:27695391

An Improved Swarm Optimization for Parameter Estimation and Biological Model Selection

PubMed Central

Abdullah, Afnizanfaizal; Deris, Safaai; Mohamad, Mohd Saberi; Anwar, Sohail

2013-01-01

One of the key aspects of computational systems biology is the investigation on the dynamic biological processes within cells. Computational models are often required to elucidate the mechanisms and principles driving the processes because of the nonlinearity and complexity. The models usually incorporate a set of parameters that signify the physical properties of the actual biological systems. In most cases, these parameters are estimated by fitting the model outputs with the corresponding experimental data. However, this is a challenging task because the available experimental data are frequently noisy and incomplete. In this paper, a new hybrid optimization method is proposed to estimate these parameters from the noisy and incomplete experimental data. The proposed method, called Swarm-based Chemical Reaction Optimization, integrates the evolutionary searching strategy employed by the Chemical Reaction Optimization, into the neighbouring searching strategy of the Firefly Algorithm method. The effectiveness of the method was evaluated using a simulated nonlinear model and two biological models: synthetic transcriptional oscillators, and extracellular protease production models. The results showed that the accuracy and computational speed of the proposed method were better than the existing Differential Evolution, Firefly Algorithm and Chemical Reaction Optimization methods. The reliability of the estimated parameters was statistically validated, which suggests that the model outputs produced by these parameters were valid even when noisy and incomplete experimental data were used. Additionally, Akaike Information Criterion was employed to evaluate the model selection, which highlighted the capability of the proposed method in choosing a plausible model based on the experimental data. In conclusion, this paper presents the effectiveness of the proposed method for parameter estimation and model selection problems using noisy and incomplete experimental data. This study is hoped to provide a new insight in developing more accurate and reliable biological models based on limited and low quality experimental data. PMID:23593445

Mouse Models in Bone Marrow Transplantation and Adoptive Cellular Therapy

PubMed Central

Arber, Caroline; Brenner, Malcolm K.; Reddy, Pavan

2014-01-01

Mouse models of transplantation have been indispensable to the development of bone marrow transplantation (BMT). Their role in the generation of basic science knowledge is invaluable and is subject to discussion below. However, this article focuses on the direct role and relevance of mouse models towards the clinical development and advances in BMT and adoptive T-cell therapy for human diseases. The authors aim to present a thoughtful perspective on the pros and cons of mouse models while noting that despite imperfections these models are obligatory for the development of science-based medicine. PMID:24216170

Incomplete initial nutation diffusion imaging: An ultrafast, single-scan approach for diffusion mapping.

PubMed

Ianuş, Andrada; Shemesh, Noam

2018-04-01

Diffusion MRI is confounded by the need to acquire at least two images separated by a repetition time, thereby thwarting the detection of rapid dynamic microstructural changes. The issue is exacerbated when diffusivity variations are accompanied by rapid changes in T 2 . The purpose of the present study is to accelerate diffusion MRI acquisitions such that both reference and diffusion-weighted images necessary for quantitative diffusivity mapping are acquired in a single-shot experiment. A general methodology termed incomplete initial nutation diffusion imaging (INDI), capturing two diffusion contrasts in a single shot, is presented. This methodology creates a longitudinal magnetization reservoir that facilitates the successive acquisition of two images separated by only a few milliseconds. The theory behind INDI is presented, followed by proof-of-concept studies in water phantom, ex vivo, and in vivo experiments at 16.4 and 9.4 T. Mean diffusivities extracted from INDI were comparable with diffusion tensor imaging and the two-shot isotropic diffusion encoding in the water phantom. In ex vivo mouse brain tissues, as well as in the in vivo mouse brain, mean diffusivities extracted from conventional isotropic diffusion encoding and INDI were in excellent agreement. Simulations for signal-to-noise considerations identified the regimes in which INDI is most beneficial. The INDI method accelerates diffusion MRI acquisition to single-shot mode, which can be of great importance for mapping dynamic microstructural properties in vivo without T 2 bias. Magn Reson Med 79:2198-2204, 2018. © 2017 The Authors Magnetic Resonance in Medicine published by Wiley Periodicals, Inc. on behalf of International Society for Magnetic Resonance in Medicine. This is an open access article under the terms of the Creative Commons Attribution License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited. © 2017 The Authors Magnetic Resonance in Medicine published by Wiley Periodicals, Inc. on behalf of International Society for Magnetic Resonance in Medicine.

Centralized mouse repositories.

PubMed

Donahue, Leah Rae; Hrabe de Angelis, Martin; Hagn, Michael; Franklin, Craig; Lloyd, K C Kent; Magnuson, Terry; McKerlie, Colin; Nakagata, Naomi; Obata, Yuichi; Read, Stuart; Wurst, Wolfgang; Hörlein, Andreas; Davisson, Muriel T

2012-10-01

Because the mouse is used so widely for biomedical research and the number of mouse models being generated is increasing rapidly, centralized repositories are essential if the valuable mouse strains and models that have been developed are to be securely preserved and fully exploited. Ensuring the ongoing availability of these mouse strains preserves the investment made in creating and characterizing them and creates a global resource of enormous value. The establishment of centralized mouse repositories around the world for distributing and archiving these resources has provided critical access to and preservation of these strains. This article describes the common and specialized activities provided by major mouse repositories around the world.

Centralized Mouse Repositories

PubMed Central

Donahue, Leah Rae; de Angelis, Martin Hrabe; Hagn, Michael; Franklin, Craig; Lloyd, K. C. Kent; Magnuson, Terry; McKerlie, Colin; Nakagata, Naomi; Obata, Yuichi; Read, Stuart; Wurst, Wolfgang; Hörlein, Andreas; Davisson, Muriel T.

2013-01-01

Because the mouse is used so widely for biomedical research and the number of mouse models being generated is increasing rapidly, centralized repositories are essential if the valuable mouse strains and models that have been developed are to be securely preserved and fully exploited. Ensuring the ongoing availability of these mouse strains preserves the investment made in creating and characterizing them and creates a global resource of enormous value. The establishment of centralized mouse repositories around the world for distributing and archiving these resources has provided critical access to and preservation of these strains. This article describes the common and specialized activities provided by major mouse repositories around the world. PMID:22945696

Connections between survey calibration estimators and semiparametric models for incomplete data

PubMed Central

Lumley, Thomas; Shaw, Pamela A.; Dai, James Y.

2012-01-01

Survey calibration (or generalized raking) estimators are a standard approach to the use of auxiliary information in survey sampling, improving on the simple Horvitz–Thompson estimator. In this paper we relate the survey calibration estimators to the semiparametric incomplete-data estimators of Robins and coworkers, and to adjustment for baseline variables in a randomized trial. The development based on calibration estimators explains the ‘estimated weights’ paradox and provides useful heuristics for constructing practical estimators. We present some examples of using calibration to gain precision without making additional modelling assumptions in a variety of regression models. PMID:23833390

On the Synchronization of EEG Spindle Waves

NASA Astrophysics Data System (ADS)

Long, Wen; Zhang, ChengFu; Zhao, SiLan; Shi, RuiHong

2000-06-01

Based on recently sleeping cellular substrates, a network model synaptically coupled by N three-cell circuits is provided. Simulation results show that: (i) the dynamic behavior of every circuit is chaotic; (ii) the synchronization of the network is incomplete; (iii) the incomplete synchronization can integrate burst firings of cortical cells into waxing-and-wanning EEG spindle waves. These results enlighten us that this kind of incomplete synchronization may integrate microscopic, electrical activities of neurons in billions into macroscopic, functional states in human brain. In addition, the effects of coupling strength, connectional mode and noise to the synchronization are discussed.

Molecular Indicators of Stress-Induced Neuroinflammation in a Mouse Model Simulating Features of Post-Traumatic Stress Disorder (Open Access)

DTIC Science & Technology

2017-05-23

OPEN ORIGINAL ARTICLE Molecular indicators of stress-induced neuroinflammation in a mouse model simulating features of post -traumatic stress disorder... post -traumatic stress disorder (PTSD). The model involved exposure of an intruder (male C57BL/6) mouse to a resident aggressor (male SJL) mouse for 5...revealed that neurogenesis and synaptic plasticity pathways were activated during the early responses but were inhibited after the later post -trauma

Genetic characterization and improved genotyping of the dysferlin-deficient mouse strain Dysf (tm1Kcam).

PubMed

Wiktorowicz, Tatiana; Kinter, Jochen; Kobuke, Kazuhiro; Campbell, Kevin P; Sinnreich, Michael

2015-01-01

Mouse models of dysferlinopathies are valuable tools with which to investigate the pathomechanisms underlying these diseases and to test novel therapeutic strategies. One such mouse model is the Dysf (tm1Kcam) strain, which was generated using a targeting vector to replace a 12-kb region of the dysferlin gene and which features a progressive muscular dystrophy. A prerequisite for successful animal studies using genetic mouse models is an accurate genotyping protocol. Unfortunately, the lack of robustness of currently available genotyping protocols for the Dysf (tm1Kcam) mouse has prevented efficient colony management. Initial attempts to improve the genotyping protocol based on the published genomic structure failed. These difficulties led us to analyze the targeted locus of the dysferlin gene of the Dysf (tm1Kcam) mouse in greater detail. In this study we resequenced and analyzed the targeted locus of the Dysf (tm1Kcam) mouse and developed a novel PCR protocol for genotyping. We found that instead of a deletion, the dysferlin locus in the Dysf (tm1Kcam) mouse carries a targeted insertion. This genetic characterization enabled us to establish a reliable method for genotyping of the Dysf (tm1Kcam) mouse, and thus has made efficient colony management possible. Our work will make the Dysf (tm1Kcam) mouse model more attractive for animal studies of dysferlinopathies.

Small Sample Statistics for Incomplete Nonnormal Data: Extensions of Complete Data Formulae and a Monte Carlo Comparison

ERIC Educational Resources Information Center

Savalei, Victoria

2010-01-01

Incomplete nonnormal data are common occurrences in applied research. Although these 2 problems are often dealt with separately by methodologists, they often cooccur. Very little has been written about statistics appropriate for evaluating models with such data. This article extends several existing statistics for complete nonnormal data to…

A Comparison of Maximum-Likelihood and Asymptotically Distribution-Free Methods of Treating Incomplete Nonnormal Data

ERIC Educational Resources Information Center

Gold, Michael S.; Bentler, Peter M.; Kim, Kevin H.

2003-01-01

This article describes a Monte Carlo study of 2 methods for treating incomplete nonnormal data. Skewed, kurtotic data sets conforming to a single structured model, but varying in sample size, percentage of data missing, and missing-data mechanism, were produced. An asymptotically distribution-free available-case (ADFAC) method and structured-model…

Limit Pricing with Incomplete Information: Answers to Frequently Asked Questions

ERIC Educational Resources Information Center

Sorenson, Timothy L.

2004-01-01

Strategic pricing is an important and exciting topic in industrial organization and the economics of strategy. A wide range of texts use what has become a standard version of the Milgrom and Roberts (1982a) limit-pricing model to convey the essential ideas of strategic pricing under incomplete information. In addition to providing a formal, but…

PoMo: An Allele Frequency-Based Approach for Species Tree Estimation

PubMed Central

De Maio, Nicola; Schrempf, Dominik; Kosiol, Carolin

2015-01-01

Incomplete lineage sorting can cause incongruencies of the overall species-level phylogenetic tree with the phylogenetic trees for individual genes or genomic segments. If these incongruencies are not accounted for, it is possible to incur several biases in species tree estimation. Here, we present a simple maximum likelihood approach that accounts for ancestral variation and incomplete lineage sorting. We use a POlymorphisms-aware phylogenetic MOdel (PoMo) that we have recently shown to efficiently estimate mutation rates and fixation biases from within and between-species variation data. We extend this model to perform efficient estimation of species trees. We test the performance of PoMo in several different scenarios of incomplete lineage sorting using simulations and compare it with existing methods both in accuracy and computational speed. In contrast to other approaches, our model does not use coalescent theory but is allele frequency based. We show that PoMo is well suited for genome-wide species tree estimation and that on such data it is more accurate than previous approaches. PMID:26209413

Modeling loosely annotated images using both given and imagined annotations

NASA Astrophysics Data System (ADS)

Tang, Hong; Boujemaa, Nozha; Chen, Yunhao; Deng, Lei

2011-12-01

In this paper, we present an approach to learn latent semantic analysis models from loosely annotated images for automatic image annotation and indexing. The given annotation in training images is loose due to: 1. ambiguous correspondences between visual features and annotated keywords; 2. incomplete lists of annotated keywords. The second reason motivates us to enrich the incomplete annotation in a simple way before learning a topic model. In particular, some ``imagined'' keywords are poured into the incomplete annotation through measuring similarity between keywords in terms of their co-occurrence. Then, both given and imagined annotations are employed to learn probabilistic topic models for automatically annotating new images. We conduct experiments on two image databases (i.e., Corel and ESP) coupled with their loose annotations, and compare the proposed method with state-of-the-art discrete annotation methods. The proposed method improves word-driven probability latent semantic analysis (PLSA-words) up to a comparable performance with the best discrete annotation method, while a merit of PLSA-words is still kept, i.e., a wider semantic range.

Mouse models of neurodegenerative diseases: criteria and general methodology.

PubMed

Janus, Christopher; Welzl, Hans

2010-01-01

The major symptom of Alzheimer's disease is rapidly progressing dementia, coinciding with the formation of amyloid and tau deposits in the central nervous system, and neuronal death. At present familial cases of dementias provide the most promising foundation for modelling neurodegeneration. We describe the mnemonic and other major behavioral symptoms of tauopathies, briefly outline the genetics underlying familiar cases and discuss the arising implications for modelling the disease in mostly transgenic mouse lines. We then depict to what degree the most recent mouse models replicate pathological and cognitive characteristics observed in patients.There is no universally valid behavioral test battery to evaluate mouse models. The selection of individual tests depends on the behavioral and/or memory system in focus, the type of a model and how well it replicates the pathology of a disease and the amount of control over the genetic background of the mouse model. However it is possible to provide guidelines and criteria for modelling the neurodegeneration, setting up the experiments and choosing relevant tests. One should not adopt a "one (trans)gene, one disease" interpretation, but should try to understand how the mouse genome copes with the protein expression of the transgene in question. Further, it is not possible to recommend some mouse models over others since each model is valuable within its own constraints, and the way experiments are performed often reflects the idiosyncratic reality of specific laboratories. Our purpose is to improve bridging molecular and behavioural approaches in translational research.

Direct comparison of the pharmacodynamics of four antifungal drugs in a mouse model of disseminated candidiasis using microbiological assays of serum drug concentrations.

PubMed

Maki, Katsuyuki; Holmes, Ann R; Watabe, Etsuko; Iguchi, Yumi; Matsumoto, Satoru; Ikeda, Fumiaki; Tawara, Shuichi; Mutoh, Seitaro

2007-01-01

The aim of this study was to compare the pharmacodynamics of the azole antifungal drugs fluconazole, itraconazole and ketoconazole, and the polyene antifungal amphotericin B, in a mouse model of disseminated Candida albicans infection. In order to directly compare effective serum concentrations of these antifungals, drug concentrations were assayed microbiologically by measuring inhibition of C. albicans mycelial growth (mMIC) in a mouse serum-based assay (serum antifungal titer). Efficacy in the mouse infection model was determined using an organ-based (kidney burden) endpoint. For all four drugs, the serum antifungal titers, 8 hr after administration of single doses of drugs at a range of drug concentrations, correlated closely with C. albicans kidney fungal burden in the mouse model. The results showed that determining serum antifungal titer may be used to accurately represent kidney fungal burden in a mouse model of disseminated candidiasis and allowed direct comparison of the pharmacodynamics of differing classes of antifungal drugs.

Mouse Models as Tools to Identify Genetic Pathways for Retinal Degeneration, as Exemplified by Leber's Congenital Amaurosis.

PubMed

Chang, Bo

2016-01-01

Leber's congenital amaurosis (LCA) is an inherited retinal degenerative disease characterized by severe loss of vision in the first year of life. In addition to early vision loss, a variety of other eye-related abnormalities including roving eye movements, deep-set eyes, and sensitivity to bright light also occur with this disease. Many animal models of LCA are available and the study them has led to a better understanding of the pathology of the disease, and has led to the development of therapeutic strategies aimed at curing or slowing down LCA. Mouse models, with their well-developed genetics and similarity to human physiology and anatomy, serve as powerful tools with which to investigate the etiology of human LCA. Such mice provide reproducible, experimental systems for elucidating pathways of normal development, function, designing strategies and testing compounds for translational research and gene-based therapies aimed at delaying the diseases progression. In this chapter, I describe tools used in the discovery and evaluation of mouse models of LCA including a Phoenix Image-Guided Optical Coherence Tomography (OCT) and a Diagnosys Espion Visual Electrophysiology System. Three mouse models are described, the rd3 mouse model for LCA12 and LCA1, the rd12 mouse model for LCA2, and the rd16 mouse model for LCA10.

Differences in Pathogenesis for Salmonella enterica serovar Typhimurium in the Mouse Versus the Swine Model Identify Bacterial Gene Products Required for Systemic but not Gastrointestinal Disease

USDA-ARS?s Scientific Manuscript database

Over the last several decades, the mouse model of Typhoid fever has been an extremely productive model to investigate Salmonella enterica serovar Typhimurium pathogenesis. The mouse is the paradigm for investigating systemic disease due to infection by Salmonella; however, the swine model of gastro...

Bifactor Models Show a Superior Model Fit: Examination of the Factorial Validity of Parent-Reported and Self-Reported Symptoms of Attention-Deficit/Hyperactivity Disorders in Children and Adolescents.

PubMed

Rodenacker, Klaas; Hautmann, Christopher; Görtz-Dorten, Anja; Döpfner, Manfred

2016-01-01

Various studies have demonstrated that bifactor models yield better solutions than models with correlated factors. However, the kind of bifactor model that is most appropriate is yet to be examined. The current study is the first to test bifactor models across the full age range (11-18 years) of adolescents using self-reports, and the first to test bifactor models with German subjects and German questionnaires. The study sample included children and adolescents aged between 6 and 18 years recruited from a German clinical sample (n = 1,081) and a German community sample (n = 642). To examine the factorial validity, we compared unidimensional, correlated factors and higher-order and bifactor models and further tested a modified incomplete bifactor model for measurement invariance. Bifactor models displayed superior model fit statistics compared to correlated factor models or second-order models. However, a more parsimonious incomplete bifactor model with only 2 specific factors (inattention and impulsivity) showed a good model fit and a better factor structure than the other bifactor models. Scalar measurement invariance was given in most group comparisons. An incomplete bifactor model would suggest that the specific inattention and impulsivity factors represent entities separable from the general attention-deficit/hyperactivity disorder construct and might, therefore, give way to a new approach to subtyping of children beyond and above attention-deficit/hyperactivity disorder. © 2016 S. Karger AG, Basel.

A unified model of the excitability of mouse sensory and motor axons.

PubMed

Makker, Preet G S; Matamala, José Manuel; Park, Susanna B; Lees, Justin G; Kiernan, Matthew C; Burke, David; Moalem-Taylor, Gila; Howells, James

2018-06-19

Non-invasive nerve excitability techniques have provided valuable insight into the understanding of neurological disorders. The widespread use of mice in translational research on peripheral nerve disorders and by pharmaceutical companies during drug development requires valid and reliable models that can be compared to humans. This study established a novel experimental protocol that enables comparative assessment of the excitability properties of motor and sensory axons at the same site in mouse caudal nerve, compared the mouse data to data for motor and sensory axons in human median nerve at the wrist, and constructed a mathematical model of the excitability of mouse axons. In a separate study, ischaemia was employed as an experimental manoeuvre to test the translational utility of this preparation. The patterns of mouse sensory and motor excitability were qualitatively similar to human studies under normal and ischaemic conditions. The most conspicuous differences between mouse and human studies were observed in the recovery cycle and the response to hyperpolarization. Modelling showed that an increase in temperature in mouse axons could account for most of the differences in the recovery cycle. The modelling also suggested a larger hyperpolarization-activated conductance in mouse axons. The kinetics of this conductance appeared to be much slower raising the possibility that an additional or different hyperpolarization-activated cyclic-nucleotide gated (HCN) channel isoform underlies the accommodation to hyperpolarization in mouse axons. Given a possible difference in HCN isoforms, caution should be exercised in extrapolating from studies of mouse motor and sensory axons to human nerve disorders. This article is protected by copyright. All rights reserved.

Rapamycin improves sociability in the BTBR T(+)Itpr3(tf)/J mouse model of autism spectrum disorders.

PubMed

Burket, Jessica A; Benson, Andrew D; Tang, Amy H; Deutsch, Stephen I

2014-01-01

Overactivation of the mammalian target of rapamycin (mTOR) has been implicated in the pathogenesis of syndromic forms of autism spectrum disorders (ASDs), such as tuberous sclerosis complex, neurofibromatosis 1, and fragile X syndrome. Administration of mTORC1 (mTOR complex 1) inhibitors (e.g. rapamycin) in syndromic mouse models of ASDs improved behavior, cognition, and neuropathology. However, since only a minority of ASDs are due to the effects of single genes (∼10%), there is a need to explore inhibition of mTOR activity in mouse models that may be more relevant to the majority of nonsyndromic presentations, such as the genetically inbred BTBR T(+)Itpr3(tf)/J (BTBR) mouse model of ASDs. BTBR mice have social impairment and exhibit increased stereotypic behavior. In prior work, d-cycloserine, a partial glycineB site agonist that targets the N-methyl-d-aspartate (NMDA) receptor, was shown to improve sociability in both Balb/c and BTBR mouse models of ASDs. Importantly, NMDA receptor activation regulates mTOR signaling activity. The current study investigated the ability of rapamycin (10mg/kg, i.p.×four days), an mTORC1 inhibitor, to improve sociability and stereotypic behavior in BTBR mice. Using a standard paradigm to assess mouse social behavior, rapamycin improved several measures of sociability in the BTBR mouse, suggesting that mTOR overactivation represents a therapeutic target that mediates or contributes to impaired sociability in the BTBR mouse model of ASDs. Interestingly, there was no effect of rapamycin on stereotypic behaviors in this mouse model. Copyright © 2013 Elsevier Inc. All rights reserved.

Approaches for Analyzing the Roles of Mast Cells and Their Proteases In Vivo

PubMed Central

Galli, Stephen J.; Tsai, Mindy; Marichal, Thomas; Tchougounova, Elena; Reber, Laurent L.; Pejler, Gunnar

2016-01-01

The roles of mast cells in health and disease remain incompletely understood. While the evidence that mast cells are critical effector cells in IgE-dependent anaphylaxis and other acute IgE-mediated allergic reactions seems unassailable, studies employing various mice deficient in mast cells or mast cell-associated proteases have yielded divergent conclusions about the roles of mast cells or their proteases in certain other immunological responses. Such “controversial” results call into question the relative utility of various older versus newer approaches to ascertain the roles of mast cells and mast cell proteases in vivo. This review discusses how both older and more recent mouse models have been used to investigate the functions of mast cells and their proteases in health and disease. We particularly focus on settings in which divergent conclusions about the importance of mast cells and their proteases have been supported by studies that employed different models of mast cell or mast cell protease deficiency. We think that two major conclusions can be drawn from such findings: (1) no matter which models of mast cell or mast cell protease deficiency one employs, the conclusions drawn from the experiments always should take into account the potential limitations of the models (particularly abnormalities affecting cell types other than mast cells) and (2) even when analyzing a biological response using a single model of mast cell or mast cell protease deficiency, details of experimental design are critical in efforts to define those conditions under which important contributions of mast cells or their proteases can be identified. PMID:25727288

Handling incomplete correlated continuous and binary outcomes in meta-analysis of individual participant data.

PubMed

Gomes, Manuel; Hatfield, Laura; Normand, Sharon-Lise

2016-09-20

Meta-analysis of individual participant data (IPD) is increasingly utilised to improve the estimation of treatment effects, particularly among different participant subgroups. An important concern in IPD meta-analysis relates to partially or completely missing outcomes for some studies, a problem exacerbated when interest is on multiple discrete and continuous outcomes. When leveraging information from incomplete correlated outcomes across studies, the fully observed outcomes may provide important information about the incompleteness of the other outcomes. In this paper, we compare two models for handling incomplete continuous and binary outcomes in IPD meta-analysis: a joint hierarchical model and a sequence of full conditional mixed models. We illustrate how these approaches incorporate the correlation across the multiple outcomes and the between-study heterogeneity when addressing the missing data. Simulations characterise the performance of the methods across a range of scenarios which differ according to the proportion and type of missingness, strength of correlation between outcomes and the number of studies. The joint model provided confidence interval coverage consistently closer to nominal levels and lower mean squared error compared with the fully conditional approach across the scenarios considered. Methods are illustrated in a meta-analysis of randomised controlled trials comparing the effectiveness of implantable cardioverter-defibrillator devices alone to implantable cardioverter-defibrillator combined with cardiac resynchronisation therapy for treating patients with chronic heart failure. © 2016 The Authors. Statistics in Medicine Published by John Wiley & Sons Ltd. © 2016 The Authors. Statistics in Medicine Published by John Wiley & Sons Ltd.

In Vivo Hyperthermic Stress Model: An Easy Tool to Study the Effects of Oxidative Stress on Neuronal Tau Functionality in Mouse Brain.

PubMed

Chauderlier, Alban; Delattre, Lucie; Buée, Luc; Galas, Marie-Christine

2017-01-01

Oxidative damage is an early event in neurodegenerative disorders such as Alzheimer disease. To increase oxidative stress in AD-related mouse models is essential to study early mechanisms involved in the physiopathology of these diseases. In this chapter, we describe an experimental mouse model of transient and acute hyperthermic stress to induce in vivo an increase of oxidative stress in the brain of any kind of wild-type or transgenic mouse.

SGLT2 mediates glucose reabsorption in the early proximal tubule.

PubMed

Vallon, Volker; Platt, Kenneth A; Cunard, Robyn; Schroth, Jana; Whaley, Jean; Thomson, Scott C; Koepsell, Hermann; Rieg, Timo

2011-01-01

Mutations in the gene encoding for the Na(+)-glucose co-transporter SGLT2 (SLC5A2) associate with familial renal glucosuria, but the role of SGLT2 in the kidney is incompletely understood. Here, we determined the localization of SGLT2 in the mouse kidney and generated and characterized SGLT2-deficient mice. In wild-type (WT) mice, immunohistochemistry localized SGLT2 to the brush border membrane of the early proximal tubule. Sglt2(-/-) mice had glucosuria, polyuria, and increased food and fluid intake without differences in plasma glucose concentrations, GFR, or urinary excretion of other proximal tubular substrates (including amino acids) compared with WT mice. SGLT2 deficiency did not associate with volume depletion, suggested by similar body weight, BP, and hematocrit; however, plasma renin concentrations were modestly higher and plasma aldosterone levels were lower in Sglt2(-/-) mice. Whole-kidney clearance studies showed that fractional glucose reabsorption was significantly lower in Sglt2(-/-) mice compared with WT mice and varied in Sglt2(-/-) mice between 10 and 60%, inversely with the amount of filtered glucose. Free-flow micropuncture revealed that for early proximal collections, 78 ± 6% of the filtered glucose was reabsorbed in WT mice compared with no reabsorption in Sglt2(-/-) mice. For late proximal collections, fractional glucose reabsorption was 93 ± 1% in WT and 21 ± 6% in Sglt2(-/-) mice, respectively. These results demonstrate that SGLT2 mediates glucose reabsorption in the early proximal tubule and most of the glucose reabsorption by the kidney, overall. This mouse model mimics and explains the glucosuric phenotype of individuals carrying SLC5A2 mutations.

Implementation of a manual for working with wobbler mice and criteria for discontinuation of the experiment.

PubMed

Ott, Bastian; Dahlke, Carolin; Meller, Karl; Napirei, Markus; Schmitt-John, Thomas; Brand-Saberi, Beate; Theiss, Carsten; Saberi, Darius

2015-07-01

Mouse breeding is of importance to a whole range of medical and biological research. There are many known mouse models for motor neuron diseases. However, it must be kept in mind that especially mouse models for amyotrophic lateral sclerosis develop severe symptoms causing intense stress. This article is designed to summarize conscientious work with the wobbler mouse, a model for the sporadic form of amyotrophic lateral sclerosis. This mouse model is characterized by a degeneration of α-motor-neurons leading to head tremor, loss of body weight and rapidly progressive paralysis. Although this mouse model has been known since 1956, there are no guidelines for breeding wobbler mice. Due to the lack of such guidelines the present study tries to close this gap and implements a manual for further studies. It includes the whole workflow in regard to wobbler mice from breeding and animal care taking, genotyping and phenotype analysis, but also gives some examples for the use of various neuronal tissues for histological investigation. Beside the progress in research a second aim should always be the enhancement of mouse welfare and reduction of stress for the laboratory animals. Copyright © 2015 Elsevier GmbH. All rights reserved.

Rational Design of Mouse Models for Cancer Research.

PubMed

Landgraf, Marietta; McGovern, Jacqui A; Friedl, Peter; Hutmacher, Dietmar W

2018-03-01

The laboratory mouse is widely considered as a valid and affordable model organism to study human disease. Attempts to improve the relevance of murine models for the investigation of human pathologies led to the development of various genetically engineered, xenograft and humanized mouse models. Nevertheless, most preclinical studies in mice suffer from insufficient predictive value when compared with cancer biology and therapy response of human patients. We propose an innovative strategy to improve the predictive power of preclinical cancer models. Combining (i) genomic, tissue engineering and regenerative medicine approaches for rational design of mouse models with (ii) rapid prototyping and computational benchmarking against human clinical data will enable fast and nonbiased validation of newly generated models. Copyright © 2017 Elsevier Ltd. All rights reserved.

Review of DoD Malaria Research Programs,

DTIC Science & Technology

1992-05-01

the irraliated sporozoite vaccine. Work in the mouse model system and then extrapolate to human malarias. Study naturally acquired immune ...recombinant vaccines. Work simultaneously in the mouse model system and with human malarias. 3. Identify targets and mechanisms of protective immunity not...multivalent vaccines that attack these same targets. 3. Working again in the mouse model, non- human primate model, andI human systems we

A novel ALS-associated variant in UBQLN4 regulates motor axon morphogenesis.

PubMed

Edens, Brittany M; Yan, Jianhua; Miller, Nimrod; Deng, Han-Xiang; Siddique, Teepu; Ma, Yongchao C

2017-05-02

The etiological underpinnings of amyotrophic lateral sclerosis (ALS) are complex and incompletely understood, although contributions to pathogenesis by regulators of proteolytic pathways have become increasingly apparent. Here, we present a novel variant in UBQLN4 that is associated with ALS and show that its expression compromises motor axon morphogenesis in mouse motor neurons and in zebrafish. We further demonstrate that the ALS-associated UBQLN4 variant impairs proteasomal function, and identify the Wnt signaling pathway effector beta-catenin as a UBQLN4 substrate. Inhibition of beta-catenin function rescues the UBQLN4 variant-induced motor axon phenotypes. These findings provide a strong link between the regulation of axonal morphogenesis and a new ALS-associated gene variant mediated by protein degradation pathways.

Animal models for prenatal gene therapy: rodent models for prenatal gene therapy.

PubMed

Roybal, Jessica L; Endo, Masayuki; Buckley, Suzanne M K; Herbert, Bronwen R; Waddington, Simon N; Flake, Alan W

2012-01-01

Fetal gene transfer has been studied in various animal models, including rabbits, guinea pigs, cats, dogs, and nonhuman primate; however, the most common model is the rodent, particularly the mouse. There are numerous advantages to mouse models, including a short gestation time of around 20 days, large litter size usually of more than six pups, ease of colony maintenance due to the small physical size, and the relatively low expense of doing so. Moreover, the mouse genome is well defined, there are many transgenic models particularly of human monogenetic disorders, and mouse-specific biological reagents are readily available. One criticism has been that it is difficult to perform procedures on the fetal mouse with suitable accuracy. Over the past decade, accumulation of technical expertise and development of technology such as high-frequency ultrasound have permitted accurate vector delivery to organs and tissues. Here, we describe our experiences of gene transfer to the fetal mouse with and without ultrasound guidance from mid to late gestation. Depending upon the vector type, the route of delivery and the age of the fetus, specific or widespread gene transfer can be achieved, making fetal mice excellent models for exploratory biodistribution studies.

New Mouse Model for Chronic Infections by Gram-Negative Bacteria Enabling the Study of Anti-Infective Efficacy and Host-Microbe Interactions

PubMed Central

Pletzer, Daniel; Mansour, Sarah C.; Wuerth, Kelli; Rahanjam, Negin

2017-01-01

ABSTRACT Only a few, relatively cumbersome animal models enable long-term Gram-negative bacterial infections that mimic human situations, where untreated infections can last for weeks. Here, we describe a simple murine cutaneous abscess model that enables chronic or progressive infections, depending on the subcutaneously injected bacterial strain. In this model, Pseudomonas aeruginosa cystic fibrosis epidemic isolate LESB58 caused localized high-density skin and soft tissue infections and necrotic skin lesions for up to 10 days but did not disseminate in either CD-1 or C57BL/6 mice. The model was adapted for use with four major Gram-negative nosocomial pathogens, Acinetobacter baumannii, Klebsiella pneumoniae, Enterobacter cloacae, and Escherichia coli. This model enabled noninvasive imaging and tracking of lux-tagged bacteria, the influx of activated neutrophils, and production of reactive oxygen-nitrogen species at the infection site. Screening antimicrobials against high-density infections showed that local but not intravenous administration of gentamicin, ciprofloxacin, and meropenem significantly but incompletely reduced bacterial counts and superficial tissue dermonecrosis. Bacterial RNA isolated from the abscess tissue revealed that Pseudomonas genes involved in iron uptake, toxin production, surface lipopolysaccharide regulation, adherence, and lipase production were highly upregulated whereas phenazine production and expression of global activator gacA were downregulated. The model was validated for studying virulence using mutants of more-virulent P. aeruginosa strain PA14. Thus, mutants defective in flagella or motility, type III secretion, or siderophore biosynthesis were noninvasive and suppressed dermal necrosis in mice, while a strain with a mutation in the bfiS gene encoding a sensor kinase showed enhanced invasiveness and mortality in mice compared to controls infected with wild-type P. aeruginosa PA14. PMID:28246361

The Canonical Wnt Pathway Drives Macropinocytosis in Cancer.

PubMed

Redelman-Sidi, Gil; Binyamin, Anna; Gaeta, Isabella; Palm, Wilhelm; Thompson, Craig B; Romesser, Paul B; Lowe, Scott W; Bagul, Mukta; Doench, John G; Root, David E; Glickman, Michael S

2018-06-05

Macropinocytosis has emerged as an important pathway of protein acquisition in cancer cells, particularly in tumors with activated Ras such as pancreatic and colon cancer. Macropinocytosis is also the route of entry of Bacillus Calmette-Guerin (BCG) and other microbial therapies of cancer. Despite this important role in tumor biology and therapy, the full mechanisms by which cancer cells can activate macropinocytosis remain incompletely defined. Using BCG uptake to assay macropinocytosis, we executed a genome-wide shRNA screen for macropinocytosis activators and identified Wnt pathway activation as a strong driver of macropinocytosis. Wnt-driven macropinocytosis was downstream of the beta catenin-dependent canonical Wnt pathway, was Pak1 dependent, and supported albumin-dependent growth in Ras-WT cells. In cells with activated Ras-dependent macropinocytosis, pharmacologic or genetic inhibition of Wnt signaling suppressed macropinocytosis. In a mouse model of Wnt-driven colonic hyperplasia via APC silencing, Wnt-activated macropinocytosis stimulated uptake of luminal microbiota, a process reversed by topical pharmacologic inhibition of macropinocytosis. Our findings indicate that Wnt pathway activation drives macropinocytosis in cancer, and its inhibition could provide a therapeutic vulnerability in Wnt-driven intestinal polyposis and cancers with Wnt activation. Copyright ©2018, American Association for Cancer Research.

Disruption of TTDA Results in Complete Nucleotide Excision Repair Deficiency and Embryonic Lethality

PubMed Central

Theil, Arjan F.; Nonnekens, Julie; Steurer, Barbara; Mari, Pierre-Olivier; de Wit, Jan; Lemaitre, Charlène; Marteijn, Jurgen A.; Raams, Anja; Maas, Alex; Vermeij, Marcel; Essers, Jeroen; Hoeijmakers, Jan H. J.; Giglia-Mari, Giuseppina; Vermeulen, Wim

2013-01-01

The ten-subunit transcription factor IIH (TFIIH) plays a crucial role in transcription and nucleotide excision repair (NER). Inactivating mutations in the smallest 8-kDa TFB5/TTDA subunit cause the neurodevelopmental progeroid repair syndrome trichothiodystrophy A (TTD-A). Previous studies have shown that TTDA is the only TFIIH subunit that appears not to be essential for NER, transcription, or viability. We studied the consequences of TTDA inactivation by generating a Ttda knock-out (Ttda−/−) mouse-model resembling TTD-A patients. Unexpectedly, Ttda−/− mice were embryonic lethal. However, in contrast to full disruption of all other TFIIH subunits, viability of Ttda−/− cells was not affected. Surprisingly, Ttda−/− cells were completely NER deficient, contrary to the incomplete NER deficiency of TTD-A patient-derived cells. We further showed that TTD-A patient mutations only partially inactivate TTDA function, explaining the relatively mild repair phenotype of TTD-A cells. Moreover, Ttda−/− cells were also highly sensitive to oxidizing agents. These findings reveal an essential role of TTDA for life, nucleotide excision repair, and oxidative DNA damage repair and identify Ttda−/− cells as a unique class of TFIIH mutants. PMID:23637614

Fructose stimulates GLP-1 but not GIP secretion in mice, rats, and humans

PubMed Central

Kuhre, Rune E.; Gribble, Fiona M.; Hartmann, Bolette; Reimann, Frank; Windeløv, Johanne A.; Rehfeld, Jens F.

2014-01-01

Nutrients often stimulate gut hormone secretion, but the effects of fructose are incompletely understood. We studied the effects of fructose on a number of gut hormones with particular focus on glucagon-like peptide 1 (GLP-1) and glucose-dependent insulinotropic polypeptide (GIP). In healthy humans, fructose intake caused a rise in blood glucose and plasma insulin and GLP-1, albeit to a lower degree than isocaloric glucose. Cholecystokinin secretion was stimulated similarly by both carbohydrates, but neither peptide YY3–36 nor glucagon secretion was affected by either treatment. Remarkably, while glucose potently stimulated GIP release, fructose was without effect. Similar patterns were found in the mouse and rat, with both fructose and glucose stimulating GLP-1 secretion, whereas only glucose caused GIP secretion. In GLUTag cells, a murine cell line used as model for L cells, fructose was metabolized and stimulated GLP-1 secretion dose-dependently (EC50 = 0.155 mM) by ATP-sensitive potassium channel closure and cell depolarization. Because fructose elicits GLP-1 secretion without simultaneous release of glucagonotropic GIP, the pathways underlying fructose-stimulated GLP-1 release might be useful targets for type 2 diabetes mellitus and obesity drug development. PMID:24525020

Binocular Goggle Augmented Imaging and Navigation System provides real-time fluorescence image guidance for tumor resection and sentinel lymph node mapping

PubMed Central

B. Mondal, Suman; Gao, Shengkui; Zhu, Nan; Sudlow, Gail P.; Liang, Kexian; Som, Avik; Akers, Walter J.; Fields, Ryan C.; Margenthaler, Julie; Liang, Rongguang; Gruev, Viktor; Achilefu, Samuel

2015-01-01

The inability to identify microscopic tumors and assess surgical margins in real-time during oncologic surgery leads to incomplete tumor removal, increases the chances of tumor recurrence, and necessitates costly repeat surgery. To overcome these challenges, we have developed a wearable goggle augmented imaging and navigation system (GAINS) that can provide accurate intraoperative visualization of tumors and sentinel lymph nodes in real-time without disrupting normal surgical workflow. GAINS projects both near-infrared fluorescence from tumors and the natural color images of tissue onto a head-mounted display without latency. Aided by tumor-targeted contrast agents, the system detected tumors in subcutaneous and metastatic mouse models with high accuracy (sensitivity = 100%, specificity = 98% ± 5% standard deviation). Human pilot studies in breast cancer and melanoma patients using a near-infrared dye show that the GAINS detected sentinel lymph nodes with 100% sensitivity. Clinical use of the GAINS to guide tumor resection and sentinel lymph node mapping promises to improve surgical outcomes, reduce rates of repeat surgery, and improve the accuracy of cancer staging. PMID:26179014

Analytical solution for reactive solute transport considering incomplete mixing within a reference elementary volume

NASA Astrophysics Data System (ADS)

Chiogna, Gabriele; Bellin, Alberto

2013-05-01

The laboratory experiments of Gramling et al. (2002) showed that incomplete mixing at the pore scale exerts a significant impact on transport of reactive solutes and that assuming complete mixing leads to overestimation of product concentration in bimolecular reactions. Successively, several attempts have been made to model this experiment, either considering spatial segregation of the reactants, non-Fickian transport applying a Continuous Time Random Walk (CTRW) or an effective upscaled time-dependent kinetic reaction term. Previous analyses of these experimental results showed that, at the Darcy scale, conservative solute transport is well described by a standard advection dispersion equation, which assumes complete mixing at the pore scale. However, reactive transport is significantly affected by incomplete mixing at smaller scales, i.e., within a reference elementary volume (REV). We consider here the family of equilibrium reactions for which the concentration of the reactants and the product can be expressed as a function of the mixing ratio, the concentration of a fictitious non reactive solute. For this type of reactions we propose, in agreement with previous studies, to model the effect of incomplete mixing at scales smaller than the Darcy scale assuming that the mixing ratio is distributed within an REV according to a Beta distribution. We compute the parameters of the Beta model by imposing that the mean concentration is equal to the value that the concentration assumes at the continuum Darcy scale, while the variance decays with time as a power law. We show that our model reproduces the concentration profiles of the reaction product measured in the Gramling et al. (2002) experiments using the transport parameters obtained from conservative experiments and an instantaneous reaction kinetic. The results are obtained applying analytical solutions both for conservative and for reactive solute transport, thereby providing a method to handle the effect of incomplete mixing on multispecies reactive solute transport, which is simpler than other previously developed methods.

Report: No Intent to Underestimate Costs Was Found, but Supporting Documentation for EPA’s Final Rule Limiting Sulfur in Gasoline Was Incomplete or Inaccurate in Several Instances

EPA Pesticide Factsheets

Report #16-P-0122, March 29, 2016. Inaccurate or incomplete documentation of the EPA's cost modeling could prevent a third party from obtaining a full and accurate understanding of how the EPA arrived at its cost estimate for the Tier 3 rule.

Six reasons why thermospheric measurements and models disagree

NASA Technical Reports Server (NTRS)

Moe, Kenneth

1987-01-01

The differences between thermospheric measurements and models are discussed. Sometimes the model is in error and at other times the measurements are, but it also is possible for both to be correct, yet have the comparison result in an apparent disagreement. These reasons are collected for disagreement, and, whenever possible, methods of reducing or eliminating them are suggested. The six causes of disagreement discussed are: actual errors caused by the limited knowledge of gas-surface interactions and by in-track winds; limitations of the thermospheric general circulation models due to incomplete knowledge of the energy sources and sinks as well as incompleteness of the parameterization which must be employed; and limitations imposed on the empirical models by the conceptual framework and the transient waves.

Treatment of d-galactose induced mouse aging with Lycium barbarum polysaccharides and its mechanism study.

PubMed

Tang, Tao; He, Bixiu

2013-01-01

We evaluated the effects of Lycium barbarum polysaccharides LBP) on D-galactose aging model mouse, and explored its possible mechanism. Kunming mice were randomly divided into the control group, the model group, the high-dose LBP group, and the low-dose LBP group. Except the control group, D-galactose was used for modelling. The drug was administrated when modelling. Mouse behavioural, learning and memory changes were observed, and the contents of lipid peroxidation (LPO), lipofuscin (LF) and monoamine oxidase B (MAO-B) in mouse brain tissue and the weight of immune organs were measured after 6 weeks. Compared with the control group, mouse weight gain in the model group reduced significantly. Compared with model group, after mice drank LBP, the times of electric shock was less than aging mice (in which, the high-dose LBP group, P<0.05), and electric shock incubation period was longer (P<0.01). On Day 45 after modelling and drug administration, the contents of LPO, LF and MAO-B in mouse brain tissue in the model group increased significantly, while those in the drug administration groups decreased significantly. The thymus index in the aging model group decreased significantly; the thymus index and the spleen index in the high-dose LBP group and the low-dose LBP group rebounded significantly (P<0.01). We concluded that LBP has an anti-aging effect on D-galactose induced aging model mouse, and its mechanism may be related with the alleviation of glucose metabolism disorder and the resistance of the generation of lipid peroxide and other substances, which damage cell membrane lipid.

Target dependence of orientation and direction selectivity of corticocortical projection neurons in the mouse V1

PubMed Central

Matsui, Teppei; Ohki, Kenichi

2013-01-01

Higher order visual areas that receive input from the primary visual cortex (V1) are specialized for the processing of distinct features of visual information. However, it is still incompletely understood how this functional specialization is acquired. Here we used in vivo two photon calcium imaging in the mouse visual cortex to investigate whether this functional distinction exists at as early as the level of projections from V1 to two higher order visual areas, AL and LM. Specifically, we examined whether sharpness of orientation and direction selectivity and optimal spatial and temporal frequency of projection neurons from V1 to higher order visual areas match with that of target areas. We found that the V1 input to higher order visual areas were indeed functionally distinct: AL preferentially received inputs from V1 that were more orientation and direction selective and tuned for lower spatial frequency compared to projection of V1 to LM, consistent with functional differences between AL and LM. The present findings suggest that selective projections from V1 to higher order visual areas initiates parallel processing of sensory information in the visual cortical network. PMID:24068987

Mutagenicity testing with transgenic mice. Part II: Comparison with the mouse spot test

PubMed Central

Wahnschaffe, Ulrich; Bitsch, Annette; Kielhorn, Janet; Mangelsdorf, Inge

2005-01-01

The mouse spot test, an in vivo mutation assay, has been used to assess a number of chemicals. It is at present the only in vivo mammalian test system capable of detecting somatic gene mutations according to OECD guidelines (OECD guideline 484). It is however rather insensitive, animal consuming and expensive type of test. More recently several assays using transgenic animals have been developed. From data in the literature, the present study compares the results of in vivo testing of over twenty chemicals using the mouse spot test and compares them with results from the two transgenic mouse models with the best data base available, the lacI model (commercially available as the Big Blue® mouse), and the lacZ model (commercially available as the Muta™ Mouse). There was agreement in the results from the majority of substances. No differences were found in the predictability of the transgenic animal assays and the mouse spot test for carcinogenicity. However, from the limited data available, it seems that the transgenic mouse assay has several advantages over the mouse spot test and may be a suitable test system replacing the mouse spot test for detection of gene but not chromosome mutations in vivo. PMID:15676065

Low-energy nuclear reaction of the 14N+169Tm system: Incomplete fusion

NASA Astrophysics Data System (ADS)

Kumar, R.; Sharma, Vijay R.; Yadav, Abhishek; Singh, Pushpendra P.; Agarwal, Avinash; Appannababu, S.; Mukherjee, S.; Singh, B. P.; Ali, R.; Bhowmik, R. K.

2017-11-01

Excitation functions of reaction residues produced in the 14N+169Tm system have been measured to high precision at energies above the fusion barrier, ranging from 1.04 VB to 1.30 VB , and analyzed in the framework of the statistical model code pace4. Analysis of α -emitting channels points toward the onset of incomplete fusion even at slightly above-barrier energies where complete fusion is supposed to be one of the dominant processes. The onset and strength of incomplete fusion have been deduced and studied in terms of various entrance channel parameters. Present results together with the reanalysis of existing data for various projectile-target combinations conclusively suggest strong influence of projectile structure on the onset of incomplete fusion. Also, a strong dependence on the Coulomb effect (ZPZT) has been observed for the present system along with different projectile-target combinations available in the literature. It is concluded that the fraction of incomplete fusion linearly increases with ZPZT and is found to be more for larger ZPZT values, indicating significantly important linear systematics.

The Mouse Genome Database (MGD): facilitating mouse as a model for human biology and disease.

PubMed

Eppig, Janan T; Blake, Judith A; Bult, Carol J; Kadin, James A; Richardson, Joel E

2015-01-01

The Mouse Genome Database (MGD, http://www.informatics.jax.org) serves the international biomedical research community as the central resource for integrated genomic, genetic and biological data on the laboratory mouse. To facilitate use of mouse as a model in translational studies, MGD maintains a core of high-quality curated data and integrates experimentally and computationally generated data sets. MGD maintains a unified catalog of genes and genome features, including functional RNAs, QTL and phenotypic loci. MGD curates and provides functional and phenotype annotations for mouse genes using the Gene Ontology and Mammalian Phenotype Ontology. MGD integrates phenotype data and associates mouse genotypes to human diseases, providing critical mouse-human relationships and access to repositories holding mouse models. MGD is the authoritative source of nomenclature for genes, genome features, alleles and strains following guidelines of the International Committee on Standardized Genetic Nomenclature for Mice. A new addition to MGD, the Human-Mouse: Disease Connection, allows users to explore gene-phenotype-disease relationships between human and mouse. MGD has also updated search paradigms for phenotypic allele attributes, incorporated incidental mutation data, added a module for display and exploration of genes and microRNA interactions and adopted the JBrowse genome browser. MGD resources are freely available to the scientific community. © The Author(s) 2014. Published by Oxford University Press on behalf of Nucleic Acids Research.

Genetically engineered mouse models of craniopharyngioma: an opportunity for therapy development and understanding of tumor biology

PubMed Central

Martinez‐Barbera, Juan Pedro

2017-01-01

Abstract Adamantinomatous craniopharyngioma (ACP) is the commonest tumor of the sellar region in childhood. Two genetically engineered mouse models have been developed and are giving valuable insights into ACP biology. These models have identified novel pathways activated in tumors, revealed an important function of paracrine signalling and extended conventional theories about the role of organ‐specific stem cells in tumorigenesis. In this review, we summarize these mouse models, what has been learnt, their limitations and open questions for future research. We then discussed how these mouse models may be used to test novel therapeutics against potentially targetable pathways recently identified in human ACP. PMID:28414891

Mouse neuroblastoma cell based model and the effect of epileptic events on calcium oscillations and neural spikes

NASA Astrophysics Data System (ADS)

Kim, Suhwan; Baek, Juyeong; Jung, Unsang; Lee, Sangwon; Jung, Woonggyu; Kim, Jeehyun; Kang, Shinwon

2013-05-01

Recently, Mouse neuroblastoma cells are considered as an attractive model for the study of human neurological and prion diseases, and intensively used as a model system in different areas. Among those areas, differentiation of neuro2a (N2A) cells, receptor mediated ion current, and glutamate induced physiological response are actively investigated. The reason for the interest to mouse neuroblastoma N2A cells is that they have a fast growing rate than other cells in neural origin with a few another advantages. This study evaluated the calcium oscillations and neural spikes recording of mouse neuroblastoma N2A cells in an epileptic condition. Based on our observation of neural spikes in mouse N2A cell with our proposed imaging modality, we report that mouse neuroblastoma N2A cells can be an important model related to epileptic activity studies. It is concluded that the mouse neuroblastoma N2A cells produce the epileptic spikes in vitro in the same way as produced by the neurons or the astrocytes. This evidence advocates the increased and strong level of neurotransmitters release by enhancement in free calcium using the 4-aminopyridine which causes the mouse neuroblastoma N2A cells to produce the epileptic spikes and calcium oscillation.

Dynamics of circulating gamma delta T cell activity in an immunocompetent mouse model of high-grade glioma

USDA-ARS?s Scientific Manuscript database

Human gamma delta T cells are potent effectors against glioma cell lines in vitro and in human/mouse xenograft models of glioblastoma, however, this effect has not been investigated in an immunocompetent mouse model. In this report, we established GL261 intracranial gliomas in syngeneic WT C57BL/6 m...

In Vivo Visualization of Bacterial Colonization, Antigen Expression, and Specific T-Cell Induction following Oral Administration of Live Recombinant Salmonella enterica Serovar Typhimurium

PubMed Central

Bumann, Dirk

2001-01-01

Live attenuated Salmonella strains that express a foreign antigen are promising oral vaccine candidates. Numerous genetic modifications have been empirically tested, but their effects on immunogenicity are difficult to interpret since important in vivo properties of recombinant Salmonella strains such as antigen expression and localization are incompletely characterized and the crucial early inductive events of an immune response to the foreign antigen are not fully understood. Here, methods were developed to directly localize and quantitate the in situ expression of an ovalbumin model antigen in recombinant Salmonella enterica serovar Typhimurium using two-color flow cytometry and confocal microscopy. In parallel, the in vivo activation, blast formation, and division of ovalbumin-specific CD4+ T cells were followed using a well-characterized transgenic T-cell receptor mouse model. This combined approach revealed a biphasic induction of ovalbumin-specific T cells in the Peyer's patches that followed the local ovalbumin expression of orally administered recombinant Salmonella cells in a dose- and time-dependent manner. Interestingly, intact Salmonella cells and cognate T cells seemed to remain in separate tissue compartments throughout induction, suggesting a transport of killed Salmonella cells from the colonized subepithelial dome area to the interfollicular inductive sites. The findings of this study will help to rationally optimize recombinant Salmonella strains as efficacious live antigen carriers for oral vaccination. PMID:11402006

Lack of species-specific difference in pulmonary function when using mouse versus human plasma in a mouse model of hemorrhagic shock.

PubMed

Peng, Zhanglong; Pati, Shibani; Fontaine, Magali J; Hall, Kelly; Herrera, Anthony V; Kozar, Rosemary A

2016-11-01

Clinical studies have demonstrated that the early and empiric use of plasma improves survival after hemorrhagic shock. We have demonstrated in rodent models of hemorrhagic shock that resuscitation with plasma is protective to the lungs compared with lactated Ringer's solution. As our long-term objective is to determine the molecular mechanisms that modulate plasma's protective effects in injured bleeding patients, we have used human plasma in a mouse model of hemorrhagic shock. The goal of the current experiments is to determine if there are significant adverse effects on lung injury when using human versus mouse plasma in an established murine model of hemorrhagic shock and laparotomy. Mice underwent laparotomy and 90 minutes of hemorrhagic shock to a mean arterial pressure (MAP) of 35 ± 5 mm Hg followed by resuscitation at 1× shed blood using either mouse fresh frozen plasma (FFP), human FFP, or human lyophilized plasma. Mean arterial pressure was recorded during shock and for the first 30 minutes of resuscitation. After 3 hours, animals were killed, and lungs collected for analysis. There was a significant increase in early MAP when mouse FFP was used to resuscitate animals compared with human FFP or human lyophilized plasma. However, despite these differences, analysis of the mouse lungs revealed no significant differences in pulmonary histopathology, lung permeability, or lung edema between all three plasma groups. Analysis of neutrophil infiltration in the lungs revealed that mouse FFP decreased neutrophil influx as measured by neutrophil staining; however, myeloperoxidase immunostaining revealed no significant differences in between groups. The study of human plasma in a mouse model of hemorrhagic shock is feasible but does reveal some differences compared with mouse plasma-based resuscitation in physiologic measures such as MAP postresuscitation. Measures of end organ function such as lung injury appear to be comparable in this acute model of hemorrhagic shock and resuscitation.

In vivo quantitative bioluminescence tomography using heterogeneous and homogeneous mouse models.

PubMed

Liu, Junting; Wang, Yabin; Qu, Xiaochao; Li, Xiangsi; Ma, Xiaopeng; Han, Runqiang; Hu, Zhenhua; Chen, Xueli; Sun, Dongdong; Zhang, Rongqing; Chen, Duofang; Chen, Dan; Chen, Xiaoyuan; Liang, Jimin; Cao, Feng; Tian, Jie

2010-06-07

Bioluminescence tomography (BLT) is a new optical molecular imaging modality, which can monitor both physiological and pathological processes by using bioluminescent light-emitting probes in small living animal. Especially, this technology possesses great potential in drug development, early detection, and therapy monitoring in preclinical settings. In the present study, we developed a dual modality BLT prototype system with Micro-computed tomography (MicroCT) registration approach, and improved the quantitative reconstruction algorithm based on adaptive hp finite element method (hp-FEM). Detailed comparisons of source reconstruction between the heterogeneous and homogeneous mouse models were performed. The models include mice with implanted luminescence source and tumor-bearing mice with firefly luciferase report gene. Our data suggest that the reconstruction based on heterogeneous mouse model is more accurate in localization and quantification than the homogeneous mouse model with appropriate optical parameters and that BLT allows super-early tumor detection in vivo based on tomographic reconstruction of heterogeneous mouse model signal.

Of Mice and Men: Comparative Analysis of Neuro-Inflammatory Mechanisms in Human and Mouse Using Cause-and-Effect Models.

PubMed

Kodamullil, Alpha Tom; Iyappan, Anandhi; Karki, Reagon; Madan, Sumit; Younesi, Erfan; Hofmann-Apitius, Martin

2017-01-01

Perturbance in inflammatory pathways have been identified as one of the major factors which leads to neurodegenerative diseases (NDD). Owing to the limited access of human brain tissues and the immense complexity of the brain, animal models, specifically mouse models, play a key role in advancing the NDD field. However, many of these mouse models fail to reproduce the clinical manifestations and end points of the disease. NDD drugs, which passed the efficacy test in mice, were repeatedly not successful in clinical trials. There are numerous studies which are supporting and opposing the applicability of mouse models in neuroinflammation and NDD. In this paper, we assessed to what extend a mouse can mimic the cellular and molecular interactions in humans at a mechanism level. Based on our mechanistic modeling approach, we investigate the failure of a neuroinflammation targeted drug in the late phases of clinical trials based on the comparative analyses between the two species.

NCI Mouse Repository | FNLCR Staging

Cancer.gov

The NCI Mouse Repository is an NCI-funded resource for mouse cancer models and associated strains. The repository makes strains available to all members of the scientific community (academic, non-profit, and commercial). NCI Mouse Repository strains

Analytical Solution for Reactive Solute Transport Considering Incomplete Mixing

NASA Astrophysics Data System (ADS)

Bellin, A.; Chiogna, G.

2013-12-01

The laboratory experiments of Gramling et al. (2002) showed that incomplete mixing at the pore scale exerts a significant impact on transport of reactive solutes and that assuming complete mixing leads to overestimation of product concentration in bimolecular reactions. We consider here the family of equilibrium reactions for which the concentration of the reactants and the product can be expressed as a function of the mixing ratio, the concentration of a fictitious non reactive solute. For this type of reactions we propose, in agreement with previous studies, to model the effect of incomplete mixing at scales smaller than the Darcy scale assuming that the mixing ratio is distributed within an REV according to a Beta distribution. We compute the parameters of the Beta model by imposing that the mean concentration is equal to the value that the concentration assumes at the continuum Darcy scale, while the variance decays with time as a power law. We show that our model reproduces the concentration profiles of the reaction product measured in the Gramling et al. (2002) experiments using the transport parameters obtained from conservative experiments and an instantaneous reaction kinetic. The results are obtained applying analytical solutions both for conservative and for reactive solute transport, thereby providing a method to handle the effect of incomplete mixing on multispecies reactive solute transport, which is simpler than other previously developed methods. Gramling, C. M., C. F. Harvey, and L. C. Meigs (2002), Reactive transport in porous media: A comparison of model prediction with laboratory visualization, Environ. Sci. Technol., 36(11), 2508-2514.

Ammonia-induced brain swelling and neurotoxicity in an organotypic slice model

PubMed Central

Back, Adam; Tupper, Kelsey Y.; Bai, Tao; Chiranand, Paulpoj; Goldenberg, Fernando D.; Frank, Jeffrey I.; Brorson, James R.

2013-01-01

Objectives Acute liver failure produces cerebral dysfunction and edema, mediated in part by elevated ammonia concentrations, often leading to coma and death. The pathophysiology of cerebral edema in acute liver failure is incompletely understood. In vitro models of the cerebral effects of acute liver failure have predominately consisted of dissociated astrocyte cultures or acute brain slices. We describe a stable long-term culture model incorporating both neural and glial elements in a three-dimensional tissue structure offering significant advantages to the study of astrocytic-neuronal interactions in the pathophysiology of cerebral edema and dysfunction in acute liver failure. Methods We utilized chronic organotypic slice cultures from mouse forebrain, applying ammonium acetate in iso-osmolar fashion for 72 hours. Imaging of slice thickness to assess for tissue swelling was accomplished in living slices with optical coherence tomography, and confocal microscopy of fluorescence immunochemical and histochemical staining served to assess astrocyte and neuronal numbers, morphology, and volume in the fixed brain slices. Results Ammonia exposure at 1–10 mM produced swelling of immunochemically-identified astrocytes, and at 10 mM resulted in macroscopic tissue swelling, with slice thickness increasing by about 30%. Astrocytes were unchanged in number. In contrast, 10 mM ammonia treatment severely disrupted neuronal morphology and reduced neuronal survival at 72 hours by one-half. Discussion Elevated ammonia produces astrocytic swelling, tissue swelling, and neuronal toxicity in cerebral tissues. Ammonia-treated organotypic brain slice cultures provide an in vitro model of cerebral effects of conditions relevant to acute liver failure, applicable to pathophysiological investigations. PMID:22196764

An extended Kalman filter for mouse tracking.

PubMed

Choi, Hongjun; Kim, Mingi; Lee, Onseok

2018-05-19

Animal tracking is an important tool for observing behavior, which is useful in various research areas. Animal specimens can be tracked using dynamic models and observation models that require several types of data. Tracking mouse has several barriers due to the physical characteristics of the mouse, their unpredictable movement, and cluttered environments. Therefore, we propose a reliable method that uses a detection stage and a tracking stage to successfully track mouse. The detection stage detects the surface area of the mouse skin, and the tracking stage implements an extended Kalman filter to estimate the state variables of a nonlinear model. The changes in the overall shape of the mouse are tracked using an oval-shaped tracking model to estimate the parameters for the ellipse. An experiment is conducted to demonstrate the performance of the proposed tracking algorithm using six video images showing various types of movement, and the ground truth values for synthetic images are compared to the values generated by the tracking algorithm. A conventional manual tracking method is also applied to compare across eight experimenters. Furthermore, the effectiveness of the proposed tracking method is also demonstrated by applying the tracking algorithm with actual images of mouse. Graphical abstract.

Mouse Models for Down Syndrome-Associated Developmental Cognitive Disabilities

PubMed Central

Liu, Chunhong; Belichenko, Pavel V.; Zhang, Li; Fu, Dawei; Kleschevnikov, Alexander M.; Baldini, Antonio; Antonarakis, Stylianos E.; Mobley, William C.; Yu, Y. Eugene

2011-01-01

Down syndrome (DS) is mainly caused by the presence of an extra copy of human chromosome 21 (Hsa21) and is a leading genetic cause for developmental cognitive disabilities in humans. The mouse is a premier model organism for DS because the regions on Hsa21 are syntenically conserved with three regions in the mouse genome, which are located on mouse chromosome 10 (Mmu10), Mmu16 and Mmu17. With the advance of chromosomal manipulation technologies, new mouse mutants have been generated to mimic DS at both the genotypic and phenotypic levels. Further mouse-based molecular genetic studies in the future may lead to the unraveling of the mechanisms underlying DS-associated developmental cognitive disabilities, which would lay the groundwork for developing effective treatments for this phenotypic manifestation. In this review, we will discuss recent progress and future challenges in modeling DS-associated developmental cognitive disability in mice with an emphasis on hippocampus-related phenotypes. PMID:21865664

Methods in Molecular Biology Mouse Genetics: Methods and Protocols | Center for Cancer Research

Cancer.gov

Mouse Genetics: Methods and Protocols provides selected mouse genetic techniques and their application in modeling varieties of human diseases. The chapters are mainly focused on the generation of different transgenic mice to accomplish the manipulation of genes of interest, tracing cell lineages, and modeling human diseases.

Use of mouse models to study the mechanisms and consequences of RBC clearance

PubMed Central

Hod, E. A.; Arinsburg, S. A.; Francis, R. O.; Hendrickson, J. E.; Zimring, J. C.; Spitalnik, S. L.

2013-01-01

Mice provide tractable animal models for studying the pathophysiology of various human disorders. This review discusses the use of mouse models for understanding red-blood-cell (RBC) clearance. These models provide important insights into the pathophysiology of various clinically relevant entities, such as autoimmune haemolytic anaemia, haemolytic transfusion reactions, other complications of RBC transfusions and immunomodulation by Rh immune globulin therapy. Mouse models of both antibody- and non-antibody-mediated RBC clearance are reviewed. Approaches for exploring unanswered questions in transfusion medicine using these models are also discussed. PMID:20345515

Generation Of A Mouse Model For Schwannomatosis

DTIC Science & Technology

2010-09-01

TITLE: Generation of a Mouse Model for Schwannomatosis PRINCIPAL INVESTIGATOR: Long-Sheng Chang, Ph.D. CONTRACTING ORGANIZATION: The...Annual 3. DATES COVERED (From - To) 1 Sep 2009 - 31 Aug 2010 4. TITLE AND SUBTITLE Generation of a Mouse Model for Schwannomatosis 5a. CONTRACT...hypothesis involving inactivation of both the INI1/SNF5 and NF2 tumor suppressor genes in the formation of schwannomatosis -associated tumors. To

Mouse Genome Database: From sequence to phenotypes and disease models

PubMed Central

Richardson, Joel E.; Kadin, James A.; Smith, Cynthia L.; Blake, Judith A.; Bult, Carol J.

2015-01-01

Summary The Mouse Genome Database (MGD, www.informatics.jax.org) is the international scientific database for genetic, genomic, and biological data on the laboratory mouse to support the research requirements of the biomedical community. To accomplish this goal, MGD provides broad data coverage, serves as the authoritative standard for mouse nomenclature for genes, mutants, and strains, and curates and integrates many types of data from literature and electronic sources. Among the key data sets MGD supports are: the complete catalog of mouse genes and genome features, comparative homology data for mouse and vertebrate genes, the authoritative set of Gene Ontology (GO) annotations for mouse gene functions, a comprehensive catalog of mouse mutations and their phenotypes, and a curated compendium of mouse models of human diseases. Here, we describe the data acquisition process, specifics about MGD's key data areas, methods to access and query MGD data, and outreach and user help facilities. genesis 53:458–473, 2015. © 2015 The Authors. Genesis Published by Wiley Periodicals, Inc. PMID:26150326

Establishing a laboratory animal model from a transgenic animal: RasH2 mice as a model for carcinogenicity studies in regulatory science.

PubMed

Urano, K; Tamaoki, N; Nomura, T

2012-01-01

Transgenic animal models have been used in small numbers in gene function studies in vivo for a period of time, but more recently, the use of a single transgenic animal model has been approved as a second species, 6-month alternative (to the routine 2-year, 2-animal model) used in short-term carcinogenicity studies for generating regulatory application data of new drugs. This article addresses many of the issues associated with the creation and use of one of these transgenic models, the rasH2 mouse, for regulatory science. The discussion includes strategies for mass producing mice with the same stable phenotype, including constructing the transgene, choosing a founder mouse, and controlling both the transgene and background genes; strategies for developing the model for regulatory science, including measurements of carcinogen susceptibility, stability of a large-scale production system, and monitoring for uniform carcinogenicity responses; and finally, efficient use of the transgenic animal model on study. Approximately 20% of mouse carcinogenicity studies for new drug applications in the United States currently use transgenic models, typically the rasH2 mouse. The rasH2 mouse could contribute to animal welfare by reducing the numbers of animals used as well as reducing the cost of carcinogenicity studies. A better understanding of the advantages and disadvantages of the transgenic rasH2 mouse will result in greater and more efficient use of this animal model in the future.

NCI Mouse Repository | Frederick National Laboratory for Cancer Research

Cancer.gov

The NCI Mouse Repository is an NCI-funded resource for mouse cancer models and associated strains. The repository makes strains available to all members of the scientific community (academic, non-profit, and commercial). NCI Mouse Repository strains

Pattern of students' conceptual change on magnetic field based on students' mental models

NASA Astrophysics Data System (ADS)

Hamid, Rimba; Widodo, Ari; Sopandi, Wahyu

2017-05-01

Students understanding about natural phenomena can be identified by analyzing their mental model. Changes in students' mental model are good indicator of students' conceptual change. This research aims at identifying students' conceptual change by analyzing changes in students' mental model. Participants of the study were twenty five elementary school students. Data were collected through throughout the lessons (prior to the lessons, during the lessons and after the lessons) based on students' written responses and individual interviews. Lessons were designed to facilitate students' conceptual change by allowing students to work in groups of students who have the similar ideas. Therefore, lessons were students-directed. Changes of students' ideas in every stage of the lessons were identified and analyzed. The results showed that there are three patterns of students' mental models, namely type of scientific (44%), analogous to everyday life (52%), and intuitive (4%). Further analyses of the pattern of their conceptual change identifies four different patterns, i.e. consistently correct (20%), consistently incomplete (16%), changing from incorrect to incomplete (8%), changing from incomplete to complete (32%), changing from complete to incorrect (4%), and changing from incorrect to complete (4%). This study suggest that the process of learning science does not move in a linear and progressive ways, rather they move in random and may move backward and forward.

The Synthesis of 44Ti and 56Ni in Massive Stars

NASA Astrophysics Data System (ADS)

Chieffi, Alessandro; Limongi, Marco

2017-02-01

We discuss the influence of rotation on the combined synthesis of {}44{Ti} and {}56{Ni} in massive stars. While {}56{Ni} is significantly produced by both complete and incomplete explosive Si burning, {}44{Ti} is mainly produced by complete explosive Si burning, with a minor contribution (in standard non-rotating models) from incomplete explosive Si burning and O burning (both explosive and hydrostatic). We find that, in most cases, the thickness of the region exposed to incomplete explosive Si burning increases in rotating models (initial velocity, v ini = 300 km s-1) and since {}56{Ni} is significantly produced in this zone, the fraction of mass coming from the complete explosive Si burning zone necessary to get the required amount of {}56{Ni} reduces. Therefore the amount of {}44{Ti} ejected for a given fixed amount of {}56{Ni} decreases in rotating models. However, some rotating models at [Fe/H] = -1 develop a very extended O convective shell in which a consistent amount of {}44{Ti} is formed, preserved, and ejected in the interstellar medium. Hence a better modeling of the thermal instabilities (convection) in the advanced burning phases together with a critical analysis of the cross sections of the nuclear reactions operating in O burning are relevant for the understanding of the synthesis of {}44{Ti}.

Quantum-like Probabilistic Models Outside Physics

NASA Astrophysics Data System (ADS)

Khrennikov, Andrei

We present a quantum-like (QL) model in that contexts (complexes of e.g. mental, social, biological, economic or even political conditions) are represented by complex probability amplitudes. This approach gives the possibility to apply the mathematical quantum formalism to probabilities induced in any domain of science. In our model quantum randomness appears not as irreducible randomness (as it is commonly accepted in conventional quantum mechanics, e.g. by von Neumann and Dirac), but as a consequence of obtaining incomplete information about a system. We pay main attention to the QL description of processing of incomplete information. Our QL model can be useful in cognitive, social and political sciences as well as economics and artificial intelligence. In this paper we consider in a more detail one special application — QL modeling of brain's functioning. The brain is modeled as a QL-computer.

Therapeutic effects of autologous lymphocytes activated with trastuzumab for xenograft mouse models of human breast cancer.

PubMed

Nakagawa, Shinichiro; Matsuoka, Yusuke; Ichihara, Hideaki; Yoshida, Hitoji; Yoshida, Kenshi; Ueoka, Ryuichi

2013-01-01

Trastuzumab (TTZ) is molecular targeted drug used for metastatic breast cancer patients overexpressing human epidermal growth factor receptor 2 (HER2). Therapeutic effects of lymphocytes activated with TTZ (TTZ-LAK) using xenograft mouse models of human breast cancer (MDA-MB-453) cells were examined in vivo. Remarkable reduction of tumor volume in a xenograft mouse models intravenously treated with TTZ-LAK cells after the subcutaneously inoculated of MDA-MB-453 cells was verified in vivo. The migration of TTZ-LAK cells in tumor of mouse models subcutaneously inoculated MDA-MB-453 cells was observed on the basis of histological analysis using immunostaining with CD-3. Induction of apoptosis in tumor of xenograft mice treated with TTZ-LAK cells was observed in micrographs using terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate nick-end labeling (TUNEL) method. It was noteworthy that the therapeutic effects of TTZ-LAK cells along with apoptosis were obtained for xenograft mouse models of human breast tumor in vivo.

Generation of a neuro-specific microarray reveals novel differentially expressed noncoding RNAs in mouse models for neurodegenerative diseases.

PubMed

Gstir, Ronald; Schafferer, Simon; Scheideler, Marcel; Misslinger, Matthias; Griehl, Matthias; Daschil, Nina; Humpel, Christian; Obermair, Gerald J; Schmuckermair, Claudia; Striessnig, Joerg; Flucher, Bernhard E; Hüttenhofer, Alexander

2014-12-01

We have generated a novel, neuro-specific ncRNA microarray, covering 1472 ncRNA species, to investigate their expression in different mouse models for central nervous system diseases. Thereby, we analyzed ncRNA expression in two mouse models with impaired calcium channel activity, implicated in Epilepsy or Parkinson's disease, respectively, as well as in a mouse model mimicking pathophysiological aspects of Alzheimer's disease. We identified well over a hundred differentially expressed ncRNAs, either from known classes of ncRNAs, such as miRNAs or snoRNAs or which represented entirely novel ncRNA species. Several differentially expressed ncRNAs in the calcium channel mouse models were assigned as miRNAs and target genes involved in calcium signaling, thus suggesting feedback regulation of miRNAs by calcium signaling. In the Alzheimer mouse model, we identified two snoRNAs, whose expression was deregulated prior to amyloid plaque formation. Interestingly, the presence of snoRNAs could be detected in cerebral spine fluid samples in humans, thus potentially serving as early diagnostic markers for Alzheimer's disease. In addition to known ncRNAs species, we also identified 63 differentially expressed, entirely novel ncRNA candidates, located in intronic or intergenic regions of the mouse genome, genomic locations, which previously have been shown to harbor the majority of functional ncRNAs. © 2014 Gstir et al.; Published by Cold Spring Harbor Laboratory Press for the RNA Society.

PDX-1 Is a Therapeutic Target for Pancreatic Cancer, Insulinoma and Islet Neoplasia Using a Novel RNA Interference Platform

PubMed Central

Liu, Shi-He; Rao, Donald D.; Nemunaitis, John; Senzer, Neil; Zhou, Guisheng; Dawson, David; Gingras, Marie-Claude; Wang, Zhaohui; Gibbs, Richard; Norman, Michael; Templeton, Nancy S.; DeMayo, Francesco J.; O'Malley, Bert; Sanchez, Robbi; Fisher, William E.; Brunicardi, F. Charles

2012-01-01

Pancreatic and duodenal homeobox-1 (PDX-1) is a transcription factor that regulates insulin expression and islet maintenance in the adult pancreas. Our recent studies demonstrate that PDX-1 is an oncogene for pancreatic cancer and is overexpressed in pancreatic cancer. The purpose of this study was to demonstrate that PDX-1 is a therapeutic target for both hormonal symptoms and tumor volume in mouse models of pancreatic cancer, insulinoma and islet neoplasia. Immunohistochemistry of human pancreatic and islet neoplasia specimens revealed marked PDX-1 overexpression, suggesting PDX-1 as a “drugable” target within these diseases. To do so, a novel RNA interference effector platform, bifunctional shRNAPDX-1, was developed and studied in mouse and human cell lines as well as in mouse models of pancreatic cancer, insulinoma and islet neoplasia. Systemic delivery of bi-shRNAhumanPDX-1 lipoplexes resulted in marked reduction of tumor volume and improved survival in a human pancreatic cancer xenograft mouse model. bi-shRNAmousePDX-1 lipoplexes prevented death from hyperinsulinemia and hypoglycemia in an insulinoma mouse model. shRNAmousePDX-1 lipoplexes reversed hyperinsulinemia and hypoglycemia in an immune-competent mouse model of islet neoplasia. PDX-1 was overexpressed in pancreatic neuroendocrine tumors and nesidioblastosis. These data demonstrate that PDX-1 RNAi therapy controls hormonal symptoms and tumor volume in mouse models of pancreatic cancer, insulinoma and islet neoplasia, therefore, PDX-1 is a potential therapeutic target for these pancreatic diseases. PMID:22905092

Development and Characterization of a Mouse Model for Marburg Hemorrhagic Fever

DTIC Science & Technology

2009-07-01

Microbiology. All Rights Reserved. Development and Characterization of a Mouse Model for Marburg Hemorrhagic Fever Kelly L. Warfield,* Steven B...mouse model has hampered an understanding of the pathogenesis and immunity of Marburg hemorrhagic fever (MHF), the disease caused by marburgvirus (MARV...cause severe hemorrhagic fevers in humans and non- human primates (27). The incubation time is estimated to be 3 to 21 days, with human case fatality

Producing a Mouse Model to Explore the Linkages Between Tocopherol Biology and Prostate Cancer

DTIC Science & Technology

2005-07-01

Edwards, Prostate cancer and supplementation with alpha-tocopherol and beta -carotene: incidence and mortality in a controlled trial. J Natl Cancer ...1-0153 TITLE: Producing a Mouse Model to Explore the Linkages Between Tocopherol Biology and Prostate Cancer ...TITLE AND SUBTITLE Producing a Mouse Model to Explore the Linkages Between Tocopherol 5a. CONTRACT NUMBER Biology and Prostate Cancer 5b. GRANT

Synergistic Action of FOXP3 and TSC1 Pathways During Tumor Progression

DTIC Science & Technology

2015-10-01

invasive carcinoma and, ultimately, metastatic disease [1-3]. Mouse models of PIN (mPIN) generated by a single- mutant gene in prostate do not progress...downstream target) is sufficient to significantly reduce the initiation of prostate cancer in the Pten conditional knockout mouse model [19-21...the possibility that these two genetic hits cooperate to promote tumor progression, and mouse models show that this cooperation accelerates

Designing Mouse Behavioral Tasks Relevant to Autistic-Like Behaviors

ERIC Educational Resources Information Center

Crawley, Jacqueline N.

2004-01-01

The importance of genetic factors in autism has prompted the development of mutant mouse models to advance our understanding of biological mechanisms underlying autistic behaviors. Mouse models of human neuropsychiatric diseases are designed to optimize (1) face validity, i.e., resemblance to the human symptoms; (2) construct validity, i.e.,…

Role of tunnelling in complete and incomplete fusion induced by 9Be on 169Tm and 187Re targets at around barrier energies

NASA Astrophysics Data System (ADS)

Kharab, Rajesh; Chahal, Rajiv; Kumar, Rajiv

2017-04-01

We have analyzed the complete and incomplete fusion excitation function for 9Be +169Tm, 187Re reactions at around barrier energies using the code PLATYPUS based on classical dynamical model. The quantum mechanical tunnelling correction is incorporated at near and sub barrier energies which significantly improves the matching between the data and prediction.

Behavioral phenotypes of genetic mouse models of autism

PubMed Central

Kazdoba, T. M.; Leach, P. T.; Crawley, J. N.

2016-01-01

More than a hundred de novo single gene mutations and copy-number variants have been implicated in autism, each occurring in a small subset of cases. Mutant mouse models with syntenic mutations offer research tools to gain an understanding of the role of each gene in modulating biological and behavioral phenotypes relevant to autism. Knockout, knockin and transgenic mice incorporating risk gene mutations detected in autism spectrum disorder and comorbid neurodevelopmental disorders are now widely available. At present, autism spectrum disorder is diagnosed solely by behavioral criteria. We developed a constellation of mouse behavioral assays designed to maximize face validity to the types of social deficits and repetitive behaviors that are central to an autism diagnosis. Mouse behavioral assays for associated symptoms of autism, which include cognitive inflexibility, anxiety, hyperactivity, and unusual reactivity to sensory stimuli, are frequently included in the phenotypic analyses. Over the past 10 years, we and many other laboratories around the world have employed these and additional behavioral tests to phenotype a large number of mutant mouse models of autism. In this review, we highlight mouse models with mutations in genes that have been identified as risk genes for autism, which work through synaptic mechanisms and through the mTOR signaling pathway. Robust, replicated autism-relevant behavioral outcomes in a genetic mouse model lend credence to a causal role for specific gene contributions and downstream biological mechanisms in the etiology of autism. PMID:26403076

Defining the role of polyamines in colon carcinogenesis using mouse models

PubMed Central

Ignatenko, Natalia A.; Gerner, Eugene W.; Besselsen, David G.

2011-01-01

Genetics and diet are both considered important risk determinants for colorectal cancer, a leading cause of death in the US and worldwide. Genetically engineered mouse (GEM) models have made a significant contribution to the characterization of colorectal cancer risk factors. Reliable, reproducible, and clinically relevant animal models help in the identification of the molecular events associated with disease progression and in the development of effictive treatment strategies. This review is focused on the use of mouse models for studying the role of polyamines in colon carcinogenesis. We describe how the available mouse models of colon cancer such as the multiple intestinal neoplasia (Min) mice and knockout genetic models facilitate understanding of the role of polyamines in colon carcinogenesis and help in the development of a rational strategy for colon cancer chemoprevention. PMID:21712957

Study of incomplete fusion reaction dynamics in 13C +165 Ho system and its dependence on various entrance channel parameters

NASA Astrophysics Data System (ADS)

Tali, Suhail A.; Kumar, Harish; Ansari, M. Afzal; Ali, Asif; Singh, D.; Ali, Rahbar; Giri, Pankaj K.; Linda, Sneha B.; Parashari, Siddharth; Kumar, R.; Singh, R. P.; Muralithar, S.

2018-02-01

The excitation functions for the evaporation residues populated in the interaction of 13C +165 Ho system have been measured at projectile energies ≈ 4-7 MeV/nucleon. Stacked foil activation technique followed by off-line γ-ray spectroscopy have been employed in the present work. The experimentally measured cross-sections are analyzed in the frame work of statistical model code PACE4, which takes into account only the complete fusion reaction cross-sections. The evaporation residues populated via xn and pxn channels were found to be in good agreement with the PACE4 predictions, while a significant enhancement in the measured cross-sections over PACE4 predictions is observed in case of α-emitting channels, which may be attributed to the incomplete fusion process. For the better understanding of incomplete fusion dynamics, the incomplete fusion fraction has also been deduced and its sensitivity with various entrance channel parameters like: projectile energy, mass-asymmetry, projectile structure in terms of Qα-value and Coulomb effect has been studied in the present work. The incomplete fusion fraction is found to increase with increasing the projectile energy and a strong projectile structure dependent mass-asymmetry systematic is also observed. The incomplete fusion fraction is also found to be small for more negative Qα-value projectile (13C) induced reactions as compared to less negative Qα-value projectiles (12C, 16O and 20Ne) induced reactions with the same target nucleus 165Ho. An interesting trend is obtained on further investigation of incomplete fusion dependence on Coulomb effect (ZPZT).

Targeting Cancer Protein Profiles with Split-Enzyme Reporter Fragments to Achieve Chemical Resolution for Molecular Imaging

DTIC Science & Technology

2013-08-01

We next tested the utility of the construct to accumulate in tumors expressing EGFR using an orthotopic mouse model for brain tumors. Glioma cells...filament tumor marker, identified implanted cells within the orthotopic mouse model which were of human origin, i.e. Gli36Δ5 cells, and demonstrated that...forward into in vivo animal tumor model studies. • In vivo imaging of EGFR targeted-complex in orthotopic mouse model of brain tumor. • Ex vivo validation

Genetically engineered mouse models of melanoma.

PubMed

Pérez-Guijarro, Eva; Day, Chi-Ping; Merlino, Glenn; Zaidi, M Raza

2017-06-01

Melanoma is a complex disease that exhibits highly heterogeneous etiological, histopathological, and genetic features, as well as therapeutic responses. Genetically engineered mouse (GEM) models provide powerful tools to unravel the molecular mechanisms critical for melanoma development and drug resistance. Here, we expound briefly the basis of the mouse modeling design, the available technology for genetic engineering, and the aspects influencing the use of GEMs to model melanoma. Furthermore, we describe in detail the currently available GEM models of melanoma. Cancer 2017;123:2089-103. © 2017 American Cancer Society. © 2017 American Cancer Society.

CRISPR-Mediated Knockout of Cybb in NSG Mice Establishes a Model of Chronic Granulomatous Disease for Human Stem-Cell Gene Therapy Transplants.

PubMed

Sweeney, Colin L; Choi, Uimook; Liu, Chengyu; Koontz, Sherry; Ha, Seung-Kwon; Malech, Harry L

2017-07-01

Chronic granulomatous disease (CGD) is characterized by defects in the production of microbicidal reactive oxygen species (ROS) by phagocytes. Testing of gene and cell therapies for the treatment of CGD in human hematopoietic cells requires preclinical transplant models. The use of the lymphocyte-deficient NOD.Cg-Prkdc scid Il2rg tm1Wjl/ SzJ (NSG) mouse strain for human hematopoietic cell xenografts to test CGD therapies is complicated by the presence of functional mouse granulocytes capable of producing ROS for subsequent bacterial and fungal killing. To establish a phagocyte-defective mouse model of X-linked CGD (X-CGD) in NSG mice, clustered regularly interspaced short palindromic repeats (CRISPR)/Cas9 was utilized for targeted knockout of mouse Cybb on the X-chromosome by microinjection of NSG mouse zygotes with Cas9 mRNA and CRISPR single-guide RNA targeting Cybb exon 1 or exon 3. This resulted in a high incidence of indel formation at the CRISPR target site, with all mice exhibiting deletions in at least one Cybb allele based on sequence analysis of tail snip DNA. A female mouse heterozygous for a 235-bp deletion in Cybb exon 1 was bred to an NSG male to establish the X-CGD NSG mouse strain, NSG.Cybb[KO]. Resulting male offspring with the 235 bp deletion were found to be defective for production of ROS by neutrophils and other phagocytes, and demonstrated increased susceptibility to spontaneous bacterial and fungal infections with granulomatous inflammation. The establishment of the phagocyte-defective NSG.Cybb[KO] mouse model enables the in vivo assessment of gene and cell therapy strategies for treating CGD in human hematopoietic cell transplants without obfuscation by functional mouse phagocytes, and may also be useful for modeling other phagocyte disorders in humanized NSG mouse xenografts.

Genetically engineered mouse models of craniopharyngioma: an opportunity for therapy development and understanding of tumor biology.

PubMed

Apps, John Richard; Martinez-Barbera, Juan Pedro

2017-05-01

Adamantinomatous craniopharyngioma (ACP) is the commonest tumor of the sellar region in childhood. Two genetically engineered mouse models have been developed and are giving valuable insights into ACP biology. These models have identified novel pathways activated in tumors, revealed an important function of paracrine signalling and extended conventional theories about the role of organ-specific stem cells in tumorigenesis. In this review, we summarize these mouse models, what has been learnt, their limitations and open questions for future research. We then discussed how these mouse models may be used to test novel therapeutics against potentially targetable pathways recently identified in human ACP. © 2017 The Authors. Brain Pathology published by John Wiley & Sons Ltd on behalf of International Society of Neuropathology.

Compensatory Limb Use and Behavioral Assessment of Motor Skill Learning Following Sensorimotor Cortex Injury in a Mouse Model of Ischemic Stroke

PubMed Central

Kerr, Abigail L.; Tennant, Kelly A.

2014-01-01

Mouse models have become increasingly popular in the field of behavioral neuroscience, and specifically in studies of experimental stroke. As models advance, it is important to develop sensitive behavioral measures specific to the mouse. The present protocol describes a skilled motor task for use in mouse models of stroke. The Pasta Matrix Reaching Task functions as a versatile and sensitive behavioral assay that permits experimenters to collect accurate outcome data and manipulate limb use to mimic human clinical phenomena including compensatory strategies (i.e., learned non-use) and focused rehabilitative training. When combined with neuroanatomical tools, this task also permits researchers to explore the mechanisms that support behavioral recovery of function (or lack thereof) following stroke. The task is both simple and affordable to set up and conduct, offering a variety of training and testing options for numerous research questions concerning functional outcome following injury. Though the task has been applied to mouse models of stroke, it may also be beneficial in studies of functional outcome in other upper extremity injury models. PMID:25045916

LungMAP: The Molecular Atlas of Lung Development Program

PubMed Central

Ardini-Poleske, Maryanne E.; Ansong, Charles; Carson, James P.; Corley, Richard A.; Deutsch, Gail H.; Hagood, James S.; Kaminski, Naftali; Mariani, Thomas J.; Potter, Steven S.; Pryhuber, Gloria S.; Warburton, David; Whitsett, Jeffrey A.; Palmer, Scott M.; Ambalavanan, Namasivayam

2017-01-01

The National Heart, Lung, and Blood Institute is funding an effort to create a molecular atlas of the developing lung (LungMAP) to serve as a research resource and public education tool. The lung is a complex organ with lengthy development time driven by interactive gene networks and dynamic cross talk among multiple cell types to control and coordinate lineage specification, cell proliferation, differentiation, migration, morphogenesis, and injury repair. A better understanding of the processes that regulate lung development, particularly alveologenesis, will have a significant impact on survival rates for premature infants born with incomplete lung development and will facilitate lung injury repair and regeneration in adults. A consortium of four research centers, a data coordinating center, and a human tissue repository provides high-quality molecular data of developing human and mouse lungs. LungMAP includes mouse and human data for cross correlation of developmental processes across species. LungMAP is generating foundational data and analysis, creating a web portal for presentation of results and public sharing of data sets, establishing a repository of young human lung tissues obtained through organ donor organizations, and developing a comprehensive lung ontology that incorporates the latest findings of the consortium. The LungMAP website (www.lungmap.net) currently contains more than 6,000 high-resolution lung images and transcriptomic, proteomic, and lipidomic human and mouse data and provides scientific information to stimulate interest in research careers for young audiences. This paper presents a brief description of research conducted by the consortium, database, and portal development and upcoming features that will enhance the LungMAP experience for a community of users. PMID:28798251

Rapid bursts of androgen-binding protein (Abp) gene duplication occurred independently in diverse mammals

PubMed Central

2008-01-01

Background The draft mouse (Mus musculus) genome sequence revealed an unexpected proliferation of gene duplicates encoding a family of secretoglobin proteins including the androgen-binding protein (ABP) α, β and γ subunits. Further investigation of 14 α-like (Abpa) and 13 β- or γ-like (Abpbg) undisrupted gene sequences revealed a rich diversity of developmental stage-, sex- and tissue-specific expression. Despite these studies, our understanding of the evolution of this gene family remains incomplete. Questions arise from imperfections in the initial mouse genome assembly and a dearth of information about the gene family structure in other rodents and mammals. Results Here, we interrogate the latest 'finished' mouse (Mus musculus) genome sequence assembly to show that the Abp gene repertoire is, in fact, twice as large as reported previously, with 30 Abpa and 34 Abpbg genes and pseudogenes. All of these have arisen since the last common ancestor with rat (Rattus norvegicus). We then demonstrate, by sequencing homologs from species within the Mus genus, that this burst of gene duplication occurred very recently, within the past seven million years. Finally, we survey Abp orthologs in genomes from across the mammalian clade and show that bursts of Abp gene duplications are not specific to the murid rodents; they also occurred recently in the lagomorph (rabbit, Oryctolagus cuniculus) and ruminant (cattle, Bos taurus) lineages, although not in other mammalian taxa. Conclusion We conclude that Abp genes have undergone repeated bursts of gene duplication and adaptive sequence diversification driven by these genes' participation in chemosensation and/or sexual identification. PMID:18269759

Distorted secretory granule composition in mast cells with multiple protease deficiency.

PubMed

Grujic, Mirjana; Calounova, Gabriela; Eriksson, Inger; Feyerabend, Thorsten; Rodewald, Hans-Reimer; Tchougounova, Elena; Kjellén, Lena; Pejler, Gunnar

2013-10-01

Mast cells are characterized by an abundance of secretory granules densely packed with inflammatory mediators such as bioactive amines, cytokines, serglycin proteoglycans with negatively charged glycosaminoglycan side chains of either heparin or chondroitin sulfate type, and large amounts of positively charged proteases. Despite the large biological impact of mast cell granules and their contents on various pathologies, the mechanisms that regulate granule composition are incompletely understood. In this study, we hypothesized that granule composition is dependent on a dynamic electrostatic interrelationship between different granule compounds. As a tool to evaluate this possibility, we generated mice in which mast cells are multideficient in a panel of positively charged proteases: the chymase mouse mast cell protease-4, the tryptase mouse mast cell protease-6, and carboxypeptidase A3. Through a posttranslational effect, mast cells from these mice additionally lack mouse mast cell protease-5 protein. Mast cells from mice deficient in individual proteases showed normal morphology. In contrast, mast cells with combined protease deficiency displayed a profound distortion of granule integrity, as seen both by conventional morphological criteria and by transmission electron microscopy. An assessment of granule content revealed that the distorted granule integrity in multiprotease-deficient mast cells was associated with a profound reduction of highly negatively charged heparin, whereas no reduction in chondroitin sulfate storage was observed. Taken together with previous findings showing that the storage of basic proteases conversely is regulated by anionic proteoglycans, these data suggest that secretory granule composition in mast cells is dependent on a dynamic interrelationship between granule compounds of opposite electrical charge.

Live imaging of mouse secondary palate fusion

PubMed Central

Kim, Seungil; Prochazka, Jan; Bush, Jeffrey O.

2017-01-01

LONG ABSTRACT The fusion of the secondary palatal shelves to form the intact secondary palate is a key process in mammalian development and its disruption can lead to cleft secondary palate, a common congenital anomaly in humans. Secondary palate fusion has been extensively studied leading to several proposed cellular mechanisms that may mediate this process. However, these studies have been mostly performed on fixed embryonic tissues at progressive timepoints during development or in fixed explant cultures analyzed at static timepoints. Static analysis is limited for the analysis of dynamic morphogenetic processes such a palate fusion and what types of dynamic cellular behaviors mediate palatal fusion is incompletely understood. Here we describe a protocol for live imaging of ex vivo secondary palate fusion in mouse embryos. To examine cellular behaviors of palate fusion, epithelial-specific Keratin14-cre was used to label palate epithelial cells in ROSA26-mTmGflox reporter embryos. To visualize filamentous actin, Lifeact-mRFPruby reporter mice were used. Live imaging of secondary palate fusion was performed by dissecting recently-adhered secondary palatal shelves of embryonic day (E) 14.5 stage embryos and culturing in agarose-containing media on a glass bottom dish to enable imaging with an inverted confocal microscope. Using this method, we have detected a variety of novel cellular behaviors during secondary palate fusion. An appreciation of how distinct cell behaviors are coordinated in space and time greatly contributes to our understanding of this dynamic morphogenetic process. This protocol can be applied to mutant mouse lines, or cultures treated with pharmacological inhibitors to further advance understanding of how secondary palate fusion is controlled. PMID:28784960

A role for γS-crystallin in the organization of actin and fiber cell maturation in the mouse lens

PubMed Central

Fan, Jianguo; Dong, Lijin; Mishra, Sanghamitra; Chen, Yingwei; FitzGerald, Paul; Wistow, Graeme

2012-01-01

γS-crystallin (γS) is a highly conserved component of the eye lens. To gain insights into the functional role(s) of this protein, the mouse gene (Crygs) was deleted. Although mutations in γS can cause severe cataracts, loss of function of γS in knockout (KO) mice produced no obvious lens opacity, but was associated with focusing defects. Electron microscopy showed no major differences in lens cell organization, suggesting that the optical defects are primarily cytoplasmic in origin. KO lenses were also grossly normal by light microscopy but showed evidence of incomplete clearance of cellular organelles in maturing fiber cells. Phalloidin labeling showed an unusual distribution of F-actin in a band of mature fiber cells in KO lenses, suggesting a defect in the organization or processing of the actin cytoskeleton. Indeed, in wild-type lenses, γS and F-actin colocalize along the fiber cell plasma membrane. Relative levels of F-actin and G-actin in wild-type and KO lenses were estimated from fluorescent staining profiles and from isolation of actin fractions from whole lenses. Both methods showed a twofold reduction in the F-actin/G-actin ratio in KO lenses, whereas no difference in tubulin organization was detected. In vitro experiments showed that recombinant mouse γS can directly stabilize F-actin. This suggests that γS may have a functional role related to actin, perhaps in ‘shepherding’ filaments to maintain the optical properties of the lens cytoplasm and normal fiber cell maturation. PMID:22715935

Rapid bursts of androgen-binding protein (Abp) gene duplication occurred independently in diverse mammals.

PubMed

Laukaitis, Christina M; Heger, Andreas; Blakley, Tyler D; Munclinger, Pavel; Ponting, Chris P; Karn, Robert C

2008-02-12

The draft mouse (Mus musculus) genome sequence revealed an unexpected proliferation of gene duplicates encoding a family of secretoglobin proteins including the androgen-binding protein (ABP) alpha, beta and gamma subunits. Further investigation of 14 alpha-like (Abpa) and 13 beta- or gamma-like (Abpbg) undisrupted gene sequences revealed a rich diversity of developmental stage-, sex- and tissue-specific expression. Despite these studies, our understanding of the evolution of this gene family remains incomplete. Questions arise from imperfections in the initial mouse genome assembly and a dearth of information about the gene family structure in other rodents and mammals. Here, we interrogate the latest 'finished' mouse (Mus musculus) genome sequence assembly to show that the Abp gene repertoire is, in fact, twice as large as reported previously, with 30 Abpa and 34 Abpbg genes and pseudogenes. All of these have arisen since the last common ancestor with rat (Rattus norvegicus). We then demonstrate, by sequencing homologs from species within the Mus genus, that this burst of gene duplication occurred very recently, within the past seven million years. Finally, we survey Abp orthologs in genomes from across the mammalian clade and show that bursts of Abp gene duplications are not specific to the murid rodents; they also occurred recently in the lagomorph (rabbit, Oryctolagus cuniculus) and ruminant (cattle, Bos taurus) lineages, although not in other mammalian taxa. We conclude that Abp genes have undergone repeated bursts of gene duplication and adaptive sequence diversification driven by these genes' participation in chemosensation and/or sexual identification.

A comparison of some organizational characteristics of the mouse central retina and the human macula.

PubMed

Volland, Stefanie; Esteve-Rudd, Julian; Hoo, Juyea; Yee, Claudine; Williams, David S

2015-01-01

Mouse models have greatly assisted our understanding of retinal degenerations. However, the mouse retina does not have a macula, leading to the question of whether the mouse is a relevant model for macular degeneration. In the present study, a quantitative comparison between the organization of the central mouse retina and the human macula was made, focusing on some structural characteristics that have been suggested to be important in predisposing the macula to stresses leading to degeneration: photoreceptor density, phagocytic load on the RPE, and the relative thinness of Bruch's membrane. Light and electron microscopy measurements from retinas of two strains of mice, together with published data on human retinas, were used for calculations and subsequent comparisons. As in the human retina, the central region of the mouse retina possesses a higher photoreceptor cell density and a thinner Bruch's membrane than in the periphery; however, the magnitudes of these periphery to center gradients are larger in the human. Of potentially greater relevance is the actual photoreceptor cell density, which is much greater in the mouse central retina than in the human macula, underlying a higher phagocytic load for the mouse RPE. Moreover, at eccentricities that correspond to the peripheral half of the human macula, the rod to cone ratio is similar between mouse and human. Hence, with respect to photoreceptor density and phagocytic load of the RPE, the central mouse retina models at least the more peripheral part of the macula, where macular degeneration is often first evident.

A Genetically Engineered Mouse Model of Neuroblastoma Driven by Mutated ALK and MYCN

DTIC Science & Technology

2014-09-01

AWARD NUMBER: W81XWH-13-1-0220 TITLE: A Genetically Engineered Mouse Model of Neuroblastoma ...CONTRACT NUMBER A Genetically Engineered Mouse Model of Neuroblastoma Driven by Mutated ALK and MYCN 5b. GRANT NUMBER W81XWH-13-1-0220 5c...common ALK mutations in neuroblastoma , F1174L and R1275Q. We have determined that in tumors cells expressing mutated ALK, different downstream

Developing Novel Therapeutic Approaches in Small Cell Lung Carcinoma Using Genetically Engineered Mouse Models and Human Circulating Tumor Cells

DTIC Science & Technology

2014-10-01

AD_________________ Award Number: W81XWH-13-1-0325 TITLE: Developing Novel Therapeutic Approaches in Small Cell Lung Carcinoma Using ...Genetically Engineered Mouse Models and Human Circulating Tumor Cells PRINCIPAL INVESTIGATOR: Jeffrey Engelman MD PhD CONTRACTING ORGANIZATION ...Novel Therapeutic Approaches in Small Cell Lung 5a. CONTRACT NUMBER W81XWH-13-1-0325 Carcinoma Using Genetically Engineered Mouse Models and 5b

Behavioural phenotyping assays for mouse models of autism

PubMed Central

Silverman, Jill L.; Yang, Mu; Lord, Catherine; Crawley, Jacqueline N.

2011-01-01

Autism is a heterogeneous neurodevelopmental disorder of unknown aetiology that affects 1 in 100–150 individuals. Diagnosis is based on three categories of behavioural criteria: abnormal social interactions, communication deficits and repetitive behaviours. Strong evidence for a genetic basis has prompted the development of mouse models with targeted mutations in candidate genes for autism. As the diagnostic criteria for autism are behavioural, phenotyping these mouse models requires behavioural assays with high relevance to each category of the diagnostic symptoms. Behavioural neuroscientists are generating a comprehensive set of assays for social interaction, communication and repetitive behaviours to test hypotheses about the causes of austism. Robust phenotypes in mouse models hold great promise as translational tools for discovering effective treatments for components of autism spectrum disorders. PMID:20559336

A developmentally plastic adult mouse kidney cell line spontaneously generates multiple adult kidney structures

DOE Office of Scientific and Technical Information (OSTI.GOV)

Webb, Carol F., E-mail: carol-webb@omrf.org; Immunobiology and Cancer Research, Oklahoma Medical Research Foundation, Oklahoma City, OK; Department of Microbiology and Immunology, University of Oklahoma Health Sciences Center, Oklahoma City, OK

Despite exciting new possibilities for regenerative therapy posed by the ability to induce pluripotent stem cells, recapitulation of three-dimensional kidneys for repair or replacement has not been possible. ARID3a-deficient mouse tissues generated multipotent, developmentally plastic cells. Therefore, we assessed the adult mouse ARID3a−/− kidney cell line, KKPS5, which expresses renal progenitor surface markers as an alternative cell source for modeling kidney development. Remarkably, these cells spontaneously developed into multicellular nephron-like structures in vitro, and engrafted into immunocompromised medaka mesonephros, where they formed mouse nephron structures. These data implicate KKPS5 cells as a new model system for studying kidney development. - Highlights:more » • An ARID3a-deficient mouse kidney cell line expresses multiple progenitor markers. • This cell line spontaneously forms multiple nephron-like structures in vitro. • This cell line formed mouse kidney structures in immunocompromised medaka fish kidneys. • Our data identify a novel model system for studying kidney development.« less

Mouse phenotyping.

PubMed

Fuchs, Helmut; Gailus-Durner, Valérie; Adler, Thure; Aguilar-Pimentel, Juan Antonio; Becker, Lore; Calzada-Wack, Julia; Da Silva-Buttkus, Patricia; Neff, Frauke; Götz, Alexander; Hans, Wolfgang; Hölter, Sabine M; Horsch, Marion; Kastenmüller, Gabi; Kemter, Elisabeth; Lengger, Christoph; Maier, Holger; Matloka, Mikolaj; Möller, Gabriele; Naton, Beatrix; Prehn, Cornelia; Puk, Oliver; Rácz, Ildikó; Rathkolb, Birgit; Römisch-Margl, Werner; Rozman, Jan; Wang-Sattler, Rui; Schrewe, Anja; Stöger, Claudia; Tost, Monica; Adamski, Jerzy; Aigner, Bernhard; Beckers, Johannes; Behrendt, Heidrun; Busch, Dirk H; Esposito, Irene; Graw, Jochen; Illig, Thomas; Ivandic, Boris; Klingenspor, Martin; Klopstock, Thomas; Kremmer, Elisabeth; Mempel, Martin; Neschen, Susanne; Ollert, Markus; Schulz, Holger; Suhre, Karsten; Wolf, Eckhard; Wurst, Wolfgang; Zimmer, Andreas; Hrabě de Angelis, Martin

2011-02-01

Model organisms like the mouse are important tools to learn more about gene function in man. Within the last 20 years many mutant mouse lines have been generated by different methods such as ENU mutagenesis, constitutive and conditional knock-out approaches, knock-down, introduction of human genes, and knock-in techniques, thus creating models which mimic human conditions. Due to pleiotropic effects, one gene may have different functions in different organ systems or time points during development. Therefore mutant mouse lines have to be phenotyped comprehensively in a highly standardized manner to enable the detection of phenotypes which might otherwise remain hidden. The German Mouse Clinic (GMC) has been established at the Helmholtz Zentrum München as a phenotyping platform with open access to the scientific community (www.mousclinic.de; [1]). The GMC is a member of the EUMODIC consortium which created the European standard workflow EMPReSSslim for the systemic phenotyping of mouse models (http://www.eumodic.org/[2]). Copyright © 2010 Elsevier Inc. All rights reserved.

Human androgen deficiency: insights gained from androgen receptor knockout mouse models

PubMed Central

Rana, Kesha; Davey, Rachel A; Zajac, Jeffrey D

2014-01-01

The mechanism of androgen action is complex. Recently, significant advances have been made into our understanding of how androgens act via the androgen receptor (AR) through the use of genetically modified mouse models. A number of global and tissue-specific AR knockout (ARKO) models have been generated using the Cre-loxP system which allows tissue- and/or cell-specific deletion. These ARKO models have examined a number of sites of androgen action including the cardiovascular system, the immune and hemopoetic system, bone, muscle, adipose tissue, the prostate and the brain. This review focuses on the insights that have been gained into human androgen deficiency through the use of ARKO mouse models at each of these sites of action, and highlights the strengths and limitations of these Cre-loxP mouse models that should be considered to ensure accurate interpretation of the phenotype. PMID:24480924

Modelling clinical systemic lupus erythematosus: similarities, differences and success stories

PubMed Central

Celhar, Teja

2017-01-01

Abstract Mouse models of SLE have been indispensable tools to study disease pathogenesis, to identify genetic susceptibility loci and targets for drug development, and for preclinical testing of novel therapeutics. Recent insights into immunological mechanisms of disease progression have boosted a revival in SLE drug development. Despite promising results in mouse studies, many novel drugs have failed to meet clinical end points. This is probably because of the complexity of the disease, which is driven by polygenic predisposition and diverse environmental factors, resulting in a heterogeneous clinical presentation. Each mouse model recapitulates limited aspects of lupus, especially in terms of the mechanism underlying disease progression. The main mouse models have been fairly successful for the evaluation of broad-acting immunosuppressants. However, the advent of targeted therapeutics calls for a selection of the most appropriate model(s) for testing and, ultimately, identification of patients who will be most likely to respond. PMID:28013204

Mouse Models of Gastric Cancer

PubMed Central

Hayakawa, Yoku; Fox, James G.; Gonda, Tamas; Worthley, Daniel L.; Muthupalani, Sureshkumar; Wang, Timothy C.

2013-01-01

Animal models have greatly enriched our understanding of the molecular mechanisms of numerous types of cancers. Gastric cancer is one of the most common cancers worldwide, with a poor prognosis and high incidence of drug-resistance. However, most inbred strains of mice have proven resistant to gastric carcinogenesis. To establish useful models which mimic human gastric cancer phenotypes, investigators have utilized animals infected with Helicobacter species and treated with carcinogens. In addition, by exploiting genetic engineering, a variety of transgenic and knockout mouse models of gastric cancer have emerged, such as INS-GAS mice and TFF1 knockout mice. Investigators have used the combination of carcinogens and gene alteration to accelerate gastric cancer development, but rarely do mouse models show an aggressive and metastatic gastric cancer phenotype that could be relevant to preclinical studies, which may require more specific targeting of gastric progenitor cells. Here, we review current gastric carcinogenesis mouse models and provide our future perspectives on this field. PMID:24216700

Phenotyping male infertility in the mouse: how to get the most out of a 'non-performer'.

PubMed

Borg, Claire L; Wolski, Katja M; Gibbs, Gerard M; O'Bryan, Moira K

2010-01-01

Functional male gametes are produced through complex processes that take place within the testis, epididymis and female reproductive tract. A breakdown at any of these phases can result in male infertility. The production of mutant mouse models often yields an unexpected male infertility phenotype. It is with this in mind that the current review has been written. The review aims to act as a guide to the 'non-reproductive biologist' to facilitate a systematic analysis of sterile or subfertile mice and to assist in extracting the maximum amount of information from each model. This is a review of the original literature on defects in the processes that take a mouse spermatogonial stem cell through to a fully functional spermatozoon, which result in male infertility. Based on literature searches and personal experience, we have outlined a step-by-step strategy for the analysis of an infertile male mouse line. A wide range of methods can be used to define the phenotype of an infertile male mouse. These methods range from histological methods such as electron microscopy and immunohistochemistry, to hormone analyses and methods to assess sperm maturation status and functional competence. With the increased rate of genetically modified mouse production, the generation of mouse models with unexpected male infertility is increasing. This manuscript will help to ensure that the maximum amount of information is obtained from each mouse model and, by extension, will facilitate the knowledge of both normal fertility processes and the causes of human infertility.

Nitroglycerin fails to lower blood pressure in redox-dead Cys42Ser PKG1α knock-in mouse

PubMed Central

Rudyk, Olena; Prysyazhna, Oleksandra; Burgoyne, Joseph R; Eaton, Philip

2013-01-01

Background Although nitroglycerin has remained in clinical use since 1879 the mechanism by which it relaxes blood vessels to lower blood pressure remains incompletely understood. Nitroglycerin undergoes metabolism generating several reaction products, including oxidants, and this ‘bioactivation’ process is essential for vasodilation. Protein kinase G (PKG) mediates classical nitric oxide-dependent vasorelaxation, but the 1α isoform is also independently activated by oxidation involving interprotein disulfide formation within this homodimeric protein complex. We hypothesised that nitroglycerin-induced vasodilation is mediated by disulfide activation of PKG1α. Methods and Results Treating smooth muscle cells or isolated blood vessels with nitroglycerin caused PKG1α disulfide dimerization. PKG1α disulfide formation was increased in wild-type mouse aortae by in vivo nitroglycerin treatment, but this oxidation was lost as tolerance developed. To establish whether kinase oxidation underlies nitroglycerin-induced vasodilation in vivo we employed a Cys42Ser PKG1α knock-in mouse that cannot transduce oxidant signals as it doesn’t contain the vital redox-sensing thiol. This ‘redox-dead’ knock-in mouse was substantively deficient in hypotensive response to nitroglycerin compared to wild-type littermates as measured in vivo using radiotelemetry. Resistance blood vessels from knock-ins were markedly less sensitive to nitroglycerin-induced vasodilation (EC50=39.2±10.7μM) than wild-types (EC50=12.1±2.9μM). Furthermore, after ~24 hours of treatment wild-type controls stopped vasodilating to nitroglycerin and the vascular sensitivity to nitroglycerin was decreased, whereas this ‘tolerance’ phenomenon that routinely hampers the management of hypertensive patients was absent in knock-ins. Conclusions PKG1α disulfide formation is a significant mediator of nitroglycerin-induced vasodilation and tolerance to nitroglycerin is associated with loss of kinase oxidation. PMID:22685118

A surgical approach appropriate for targeted cochlear gene therapy in the mouse.

PubMed

Jero, J; Tseng, C J; Mhatre, A N; Lalwani, A K

2001-01-01

Therapeutic manipulations of the mammalian cochlea, including cochlear gene transfer, have been predominantly studied using the guinea pig as the experimental model. With the significant developments in mouse genomics and the availability of mutant strains of mice with well-characterized hearing loss, the mouse justifiably will be the preferred animal model for therapeutic manipulations. However, the potential advantages of the mouse model have not been fully realized due to the surgical difficulty of accessing its small cochlea. This study describes a ventral approach, instead of the routinely used postauricular approach in other rodents, for accessing the mouse middle and inner ear, and its application in cochlear gene transfer. This ventral approach enabled rapid and direct delivery of liposome-transgene complex to the mouse inner ear while avoiding blood loss, facial nerve morbidity, and mortality. Transgene expression at 3 days was detected in Reissner's membrane, spiral limbus, spiral ligament, and spiral ganglion cells, in a pattern similar to that previously described in the guinea pig. The successful access and delivery of material to the mouse cochlea and the replication of gene expression seen in the guinea pig demonstrated in this study should promote the use of the mouse in future studies investigating targeted cochlear therapy.

Bi-level Multi-Source Learning for Heterogeneous Block-wise Missing Data

PubMed Central

Xiang, Shuo; Yuan, Lei; Fan, Wei; Wang, Yalin; Thompson, Paul M.; Ye, Jieping

2013-01-01

Bio-imaging technologies allow scientists to collect large amounts of high-dimensional data from multiple heterogeneous sources for many biomedical applications. In the study of Alzheimer's Disease (AD), neuroimaging data, gene/protein expression data, etc., are often analyzed together to improve predictive power. Joint learning from multiple complementary data sources is advantageous, but feature-pruning and data source selection are critical to learn interpretable models from high-dimensional data. Often, the data collected has block-wise missing entries. In the Alzheimer’s Disease Neuroimaging Initiative (ADNI), most subjects have MRI and genetic information, but only half have cerebrospinal fluid (CSF) measures, a different half has FDG-PET; only some have proteomic data. Here we propose how to effectively integrate information from multiple heterogeneous data sources when data is block-wise missing. We present a unified “bi-level” learning model for complete multi-source data, and extend it to incomplete data. Our major contributions are: (1) our proposed models unify feature-level and source-level analysis, including several existing feature learning approaches as special cases; (2) the model for incomplete data avoids imputing missing data and offers superior performance; it generalizes to other applications with block-wise missing data sources; (3) we present efficient optimization algorithms for modeling complete and incomplete data. We comprehensively evaluate the proposed models including all ADNI subjects with at least one of four data types at baseline: MRI, FDG-PET, CSF and proteomics. Our proposed models compare favorably with existing approaches. PMID:23988272

Bi-level multi-source learning for heterogeneous block-wise missing data.

PubMed

Xiang, Shuo; Yuan, Lei; Fan, Wei; Wang, Yalin; Thompson, Paul M; Ye, Jieping

2014-11-15

Bio-imaging technologies allow scientists to collect large amounts of high-dimensional data from multiple heterogeneous sources for many biomedical applications. In the study of Alzheimer's Disease (AD), neuroimaging data, gene/protein expression data, etc., are often analyzed together to improve predictive power. Joint learning from multiple complementary data sources is advantageous, but feature-pruning and data source selection are critical to learn interpretable models from high-dimensional data. Often, the data collected has block-wise missing entries. In the Alzheimer's Disease Neuroimaging Initiative (ADNI), most subjects have MRI and genetic information, but only half have cerebrospinal fluid (CSF) measures, a different half has FDG-PET; only some have proteomic data. Here we propose how to effectively integrate information from multiple heterogeneous data sources when data is block-wise missing. We present a unified "bi-level" learning model for complete multi-source data, and extend it to incomplete data. Our major contributions are: (1) our proposed models unify feature-level and source-level analysis, including several existing feature learning approaches as special cases; (2) the model for incomplete data avoids imputing missing data and offers superior performance; it generalizes to other applications with block-wise missing data sources; (3) we present efficient optimization algorithms for modeling complete and incomplete data. We comprehensively evaluate the proposed models including all ADNI subjects with at least one of four data types at baseline: MRI, FDG-PET, CSF and proteomics. Our proposed models compare favorably with existing approaches. © 2013 Elsevier Inc. All rights reserved.

Behavioral phenotypes of genetic mouse models of autism.

PubMed

Kazdoba, T M; Leach, P T; Crawley, J N

2016-01-01

More than a hundred de novo single gene mutations and copy-number variants have been implicated in autism, each occurring in a small subset of cases. Mutant mouse models with syntenic mutations offer research tools to gain an understanding of the role of each gene in modulating biological and behavioral phenotypes relevant to autism. Knockout, knockin and transgenic mice incorporating risk gene mutations detected in autism spectrum disorder and comorbid neurodevelopmental disorders are now widely available. At present, autism spectrum disorder is diagnosed solely by behavioral criteria. We developed a constellation of mouse behavioral assays designed to maximize face validity to the types of social deficits and repetitive behaviors that are central to an autism diagnosis. Mouse behavioral assays for associated symptoms of autism, which include cognitive inflexibility, anxiety, hyperactivity, and unusual reactivity to sensory stimuli, are frequently included in the phenotypic analyses. Over the past 10 years, we and many other laboratories around the world have employed these and additional behavioral tests to phenotype a large number of mutant mouse models of autism. In this review, we highlight mouse models with mutations in genes that have been identified as risk genes for autism, which work through synaptic mechanisms and through the mTOR signaling pathway. Robust, replicated autism-relevant behavioral outcomes in a genetic mouse model lend credence to a causal role for specific gene contributions and downstream biological mechanisms in the etiology of autism. © 2015 John Wiley & Sons Ltd and International Behavioural and Neural Genetics Society.

Using Genetic Mouse Models to Gain Insight into Glaucoma: Past Results and Future Possibilities

PubMed Central

Fernandes, Kimberly A.; Harder, Jeffrey M.; Williams, Pete A.; Rausch, Rebecca L.; Kiernan, Amy E.; Nair, K. Saidas; Anderson, Michael G.; John, Simon W.; Howell, Gareth R.; Libby, Richard T.

2015-01-01

While all forms of glaucoma are characterized by a specific pattern of retinal ganglion cell death, they are clinically divided into several distinct subclasses, including normal tension glaucoma, primary open angle glaucoma, congenital glaucoma, and secondary glaucoma. For each type of glaucoma there are likely numerous molecular pathways that control susceptibility to the disease. Given this complexity, a single animal model will never precisely model all aspects of all the different types of human glaucoma. Therefore, multiple animal models have been utilized to study glaucoma but more are needed. Because of the powerful genetic tools available to use in the laboratory mouse, it has proven to be a highly useful mammalian system for studying the pathophysiology of human disease. The similarity between human and mouse eyes coupled with the ability to use a combination of advanced cell biological and genetic tools in mice have led to a large increase in the number of studies using mice to model specific glaucoma phenotypes. Over the last decade, numerous new mouse models and genetic tools have emerged, providing important insight into the cell biology and genetics of glaucoma. In this review, we describe available mouse genetic models that can be used to study glaucoma-relevant disease/pathobiology. Furthermore, we discuss how these models have been used to gain insights into ocular hypertension (a major risk factor for glaucoma) and glaucomatous retinal ganglion cell death. Finally, the potential for developing new mouse models and using advanced genetic tools and resources for studying glaucoma are discussed. PMID:26116903

Neurocognitive endophenotypes in CGG KI and Fmr1 KO mouse models of Fragile X-Associated disorders: an analysis of the state of the field

PubMed Central

Hunsaker, Michael R.

2013-01-01

It has become increasingly important that the field of behavioral genetics identifies not only the gross behavioral phenotypes associated with a given mutation, but also the behavioral endophenotypes that scale with the dosage of the particular mutation being studied. Over the past few years, studies evaluating the effects of the polymorphic CGG trinucleotide repeat on the FMR1 gene underlying Fragile X-Associated Disorders have reported preliminary evidence for a behavioral endophenotype in human Fragile X Premutation carrier populations as well as the CGG knock-in (KI) mouse model. More recently, the behavioral experiments used to test the CGG KI mouse model have been extended to the Fmr1 knock-out (KO) mouse model. When combined, these data provide compelling evidence for a clear neurocognitive endophenotype in the mouse models of Fragile X-Associated Disorders such that behavioral deficits scale predictably with genetic dosage. Similarly, it appears that the CGG KI mouse effectively models the histopathology in Fragile X-Associated Disorders across CGG repeats well into the full mutation range, resulting in a reliable histopathological endophenotype. These endophenotypes may influence future research directions into treatment strategies for not only Fragile X Syndrome, but also the Fragile X Premutation and Fragile X-Associated Tremor/Ataxia Syndrome (FXTAS). PMID:24627796

Long non-coding RNA expression patterns in lung tissues of chronic cigarette smoke induced COPD mouse model.

PubMed

Zhang, Haiyun; Sun, Dejun; Li, Defu; Zheng, Zeguang; Xu, Jingyi; Liang, Xue; Zhang, Chenting; Wang, Sheng; Wang, Jian; Lu, Wenju

2018-05-15

Long non-coding RNAs (lncRNAs) have critical regulatory roles in protein-coding gene expression. Aberrant expression profiles of lncRNAs have been observed in various human diseases. In this study, we investigated transcriptome profiles in lung tissues of chronic cigarette smoke (CS)-induced COPD mouse model. We found that 109 lncRNAs and 260 mRNAs were significantly differential expressed in lungs of chronic CS-induced COPD mouse model compared with control animals. GO and KEGG analyses indicated that differentially expressed lncRNAs associated protein-coding genes were mainly involved in protein processing of endoplasmic reticulum pathway, and taurine and hypotaurine metabolism pathway. The combination of high throughput data analysis and the results of qRT-PCR validation in lungs of chronic CS-induced COPD mouse model, 16HBE cells with CSE treatment and PBMC from patients with COPD revealed that NR_102714 and its associated protein-coding gene UCHL1 might be involved in the development of COPD both in mouse and human. In conclusion, our study demonstrated that aberrant expression profiles of lncRNAs and mRNAs existed in lungs of chronic CS-induced COPD mouse model. From animal models perspective, these results might provide further clues to investigate biological functions of lncRNAs and their potential target protein-coding genes in the pathogenesis of COPD.

Fitting models of continuous trait evolution to incompletely sampled comparative data using approximate Bayesian computation.

PubMed

Slater, Graham J; Harmon, Luke J; Wegmann, Daniel; Joyce, Paul; Revell, Liam J; Alfaro, Michael E

2012-03-01

In recent years, a suite of methods has been developed to fit multiple rate models to phylogenetic comparative data. However, most methods have limited utility at broad phylogenetic scales because they typically require complete sampling of both the tree and the associated phenotypic data. Here, we develop and implement a new, tree-based method called MECCA (Modeling Evolution of Continuous Characters using ABC) that uses a hybrid likelihood/approximate Bayesian computation (ABC)-Markov-Chain Monte Carlo approach to simultaneously infer rates of diversification and trait evolution from incompletely sampled phylogenies and trait data. We demonstrate via simulation that MECCA has considerable power to choose among single versus multiple evolutionary rate models, and thus can be used to test hypotheses about changes in the rate of trait evolution across an incomplete tree of life. We finally apply MECCA to an empirical example of body size evolution in carnivores, and show that there is no evidence for an elevated rate of body size evolution in the pinnipeds relative to terrestrial carnivores. ABC approaches can provide a useful alternative set of tools for future macroevolutionary studies where likelihood-dependent approaches are lacking. © 2011 The Author(s). Evolution© 2011 The Society for the Study of Evolution.

Modeling bladder cancer in mice: opportunities and challenges

PubMed Central

Kobayashi, Takashi; Owczarek, Tomasz B.; McKiernan, James M.; Abate-Shen, Cory

2015-01-01

The prognosis and treatment of bladder cancer have hardly improved in the last 20 years. Bladder cancer remains a debilitating and often fatal disease, and among the most costly cancers to treat. The generation of informative mouse models has the potential to improve our understanding of bladder cancer progression, as well as impact its diagnosis and treatment. However, relatively few mouse models of bladder cancer have been described and particularly few that develop invasive cancer phenotypes. This review focuses on opportunities for improving the landscape of mouse models of bladder cancer. PMID:25533675

Development and function of human innate immune cells in a humanized mouse model.

PubMed

Rongvaux, Anthony; Willinger, Tim; Martinek, Jan; Strowig, Till; Gearty, Sofia V; Teichmann, Lino L; Saito, Yasuyuki; Marches, Florentina; Halene, Stephanie; Palucka, A Karolina; Manz, Markus G; Flavell, Richard A

2014-04-01

Mice repopulated with human hematopoietic cells are a powerful tool for the study of human hematopoiesis and immune function in vivo. However, existing humanized mouse models cannot support development of human innate immune cells, including myeloid cells and natural killer (NK) cells. Here we describe two mouse strains called MITRG and MISTRG, in which human versions of four genes encoding cytokines important for innate immune cell development are knocked into their respective mouse loci. The human cytokines support the development and function of monocytes, macrophages and NK cells derived from human fetal liver or adult CD34(+) progenitor cells injected into the mice. Human macrophages infiltrated a human tumor xenograft in MITRG and MISTRG mice in a manner resembling that observed in tumors obtained from human patients. This humanized mouse model may be used to model the human immune system in scenarios of health and pathology, and may enable evaluation of therapeutic candidates in an in vivo setting relevant to human physiology.

Development and function of human innate immune cells in a humanized mouse model

PubMed Central

Rongvaux, Anthony; Willinger, Tim; Martinek, Jan; Strowig, Till; Gearty, Sofia V.; Teichmann, Lino L.; Saito, Yasuyuki; Marches, Florentina; Halene, Stephanie; Palucka, A. Karolina; Manz, Markus G.; Flavell, Richard A.

2014-01-01

Mice repopulated with human hematopoietic cells are a powerful tool for the study of human hematopoiesis and immune function in vivo. However, existing humanized mouse models are unable to support development of human innate immune cells, including myeloid cells and NK cells. Here we describe a mouse strain, called MI(S)TRG, in which human versions of four genes encoding cytokines important for innate immune cell development are knocked in to their respective mouse loci. The human cytokines support the development and function of monocytes/macrophages and natural killer cells derived from human fetal liver or adult CD34+ progenitor cells injected into the mice. Human macrophages infiltrated a human tumor xenograft in MI(S)TRG mice in a manner resembling that observed in tumors obtained from human patients. This humanized mouse model may be used to model the human immune system in scenarios of health and pathology, and may enable evaluation of therapeutic candidates in an in vivo setting relevant to human physiology. PMID:24633240

Effect of electroacupuncture on brain-derived neurotrophic factor mRNA expression in mouse hippocampus following cerebral ischemia-reperfusion injury.

PubMed

Zhao, Jianxin; Xu, Huazhou; Tian, Yuanxiang; Hu, Manxiang; Xiao, Hongling

2013-04-01

This work aims to observe the effects of electroacupuncture on brain-derived neurotrophic factor (BDNF) mRNA expression in mouse hippocampus following cerebral ischemia-reperfusion injury. The models of mouse cerebral ischemia-reperfusion injury were established. A total of 96 healthy mice were randomly assigned into 4 groups, namely, the sham surgery, model, model + electroacupuncture, and mode + hydergine groups. Mice in the model + electroacupuncture group were treated through electroacupuncture at the Shenshu (BL 23), Geshu (BL 17), and Baihui (GV 20) acupoints. Mice in the model+hydergine group were intragastrically administered with hydergine (0.77 mg/kg(-1) x day(-1)). The levels of BDNF mRNA expressions in the hippocampus were ana lyzed through a semi-quantitative reverse transcription-polymerase chain reaction assay on days 1 and 7 after the surgeries. BDNF mRNA expressions in the mouse hippocampus of the model group on days 1 and 7 after the surgery were higher than those of the sham surgery group (both P < 0.01). On days 1 and 7 of the electroacupuncture treatment, BDNF mRNA expression in the mouse hippocampus of the model + electroacupuncture group was significantly elevated compared with the model group (both P < 0.01) or the model + hydergine group (both P < 0.01). On days 1 and 7 of the hydergine treatment, BDNF mRNA expression in the mouse hippocampus of the model + hydergine group tended to increase compared with the model group; however, statistical significance was not achieved (both P > 0.05). Electroacupuncture treatment enhances endogenous BDNF expression, which may improve the survival environment for intracerebral neurons and inhibit the apoptosis of hippocampal cells.

Estimating transmission of avian influenza in wild birds from incomplete epizootic data: implications for surveillance and disease spreac

USGS Publications Warehouse

Henaux, Viviane; Jane Parmley,; Catherine Soos,; Samuel, Michael D.

2013-01-01

Synthesis and applications. Our study highlights the potential of integrating incomplete surveillance data with epizootic models to quantify disease transmission and immunity. This modelling approach provides an important tool to understand spatial and temporal epizootic dynamics and inform disease surveillance. Our findings suggest focusing highly pathogenic avian influenza virus (HPAIv) surveillance on postbreeding areas where mortality of immunologically naïve hatch-year birds is most likely to occur, and collecting serology to enhance HPAIv detection. Our modelling approach can integrate various types of disease data facilitating its use with data from other surveillance programs (as illustrated by the estimation of infection rate during an HPAIv outbreak in mute swansCygnus olor in Europe).

Intramyocardial Injection of siRNAs Can Efficiently Establish Myocardial Tissue-Specific Renalase Knockdown Mouse Model.

PubMed

Huang, Kun; Liu, Ju; Zhang, Hui; Wang, Jiliang; Li, Huili

2016-01-01

Ischaemia/reperfusion (I/R) injury will cause additional death of cardiomyocytes in ischaemic heart disease. Recent studies revealed that renalase was involved in the I/R injury. So, the myocardial tissue-specific knockdown mouse models were needed for the investigations of renalase. To establish the mouse models, intramyocardial injection of siRNAs targeting renalase was performed in mice. The wild distribution and high transfection efficiency of the siRNAs were approved. And the renalase expression was efficiently suppressed in myocardial tissue. Compared with the high cost, time consumption, and genetic compensation risk of the Cre/loxP technology, RNA interference (RNAi) technology is much cheaper and less time-consuming. Among the RNAi technologies, injection of siRNAs is safer than virus. And considering the properties of the I/R injury mouse models, the efficiency and durability of injection with siRNAs are acceptable for the studies. Altogether, intramyocardial injection of siRNAs targeting renalase is an economical, safe, and efficient method to establish myocardial tissue-specific renalase knockdown mouse models.

Improvements and Limitations of Humanized Mouse Models for HIV Research: NIH/NIAID "Meet the Experts" 2015 Workshop Summary.

PubMed

Akkina, Ramesh; Allam, Atef; Balazs, Alejandro B; Blankson, Joel N; Burnett, John C; Casares, Sofia; Garcia, J Victor; Hasenkrug, Kim J; Kashanchi, Fatah; Kitchen, Scott G; Klein, Florian; Kumar, Priti; Luster, Andrew D; Poluektova, Larisa Y; Rao, Mangala; Sanders-Beer, Brigitte E; Shultz, Leonard D; Zack, Jerome A

2016-02-01

The number of humanized mouse models for the human immunodeficiency virus (HIV)/acquired immunodeficiency syndrome (AIDS) and other infectious diseases has expanded rapidly over the past 8 years. Highly immunodeficient mouse strains, such as NOD/SCID/gamma chain(null) (NSG, NOG), support better human hematopoietic cell engraftment. Another improvement is the derivation of highly immunodeficient mice, transgenic with human leukocyte antigens (HLAs) and cytokines that supported development of HLA-restricted human T cells and heightened human myeloid cell engraftment. Humanized mice are also used to study the HIV reservoir using new imaging techniques. Despite these advances, there are still limitations in HIV immune responses and deficits in lymphoid structures in these models in addition to xenogeneic graft-versus-host responses. To understand and disseminate the improvements and limitations of humanized mouse models to the scientific community, the NIH sponsored and convened a meeting on April 15, 2015 to discuss the state of knowledge concerning these questions and best practices for selecting a humanized mouse model for a particular scientific investigation. This report summarizes the findings of the NIH meeting.

Oral recombinant human or mouse lactoferrin reduces Mycobacterium tuberculosis TDM induced granulomatous lung pathology.

PubMed

Hwang, Shen-An; Kruzel, Marian L; Actor, Jeffrey K

2017-02-01

Trehalose 6'6-dimycolate (TDM) is the most abundant glycolipid on the cell wall of Mycobacterium tuberculosis (MTB). TDM is capable of inducing granulomatous pathology in mouse models that resembles those induced by MTB infection. Using the acute TDM model, this work investigates the effect of recombinant human and mouse lactoferrin to reduce granulomatous pathology. C57BL/6 mice were injected intravenously with TDM at a dose of 25 μg·mouse -1 . At day 4 and 6, recombinant human or mouse lactoferrin (1 mg·(100 μL) -1 ·mouse -1 ) were delivered by gavage. At day 7 after TDM injection, mice were evaluated for lung pathology, cytokine production, and leukocyte populations. Mice given human or mouse lactoferrin had reduced production of IL-12p40 in their lungs. Mouse lactoferrin increased IL-6 and KC (CXCL1) in lung tissue. Increased numbers of macrophages were observed in TDM-injected mice given human or mouse lactoferrin. Granulomatous pathology, composed of mainly migrated leukocytes, was visually reduced in mice that received human or mouse lactoferrin. Quantitation of granulomatous pathology demonstrated a significant decrease in mice given human or mouse lactoferrin compared with TDM control mice. This report is the first to directly compare the immune modulatory effects of both heterologous recombinant human and homologous mouse lactoferrin on the development of TDM-induced granulomas.

Mouse neuroblastoma cell-based model and the effect of epileptic events on calcium oscillations and neural spikes

NASA Astrophysics Data System (ADS)

Kim, Suhwan; Jung, Unsang; Baek, Juyoung; Lee, Sangwon; Jung, Woonggyu; Kim, Jeehyun; Kang, Shinwon

2013-01-01

Recently, mouse neuroblastoma cells have been considered as an attractive model for the study of human neurological and prion diseases, and they have been intensively used as a model system in different areas. For example, the differentiation of neuro2a (N2A) cells, receptor-mediated ion current, and glutamate-induced physiological responses have been actively investigated with these cells. These mouse neuroblastoma N2A cells are of interest because they grow faster than other cells of neural origin and have a number of other advantages. The calcium oscillations and neural spikes of mouse neuroblastoma N2A cells in epileptic conditions are evaluated. Based on our observations of neural spikes in these cells with our proposed imaging modality, we reported that they can be an important model in epileptic activity studies. We concluded that mouse neuroblastoma N2A cells produce epileptic spikes in vitro in the same way as those produced by neurons or astrocytes. This evidence suggests that increased levels of neurotransmitter release due to the enhancement of free calcium from 4-aminopyridine causes the mouse neuroblastoma N2A cells to produce epileptic spikes and calcium oscillations.

High-fertility phenotypes: two outbred mouse models exhibit substantially different molecular and physiological strategies warranting improved fertility.

PubMed

Langhammer, Martina; Michaelis, Marten; Hoeflich, Andreas; Sobczak, Alexander; Schoen, Jennifer; Weitzel, Joachim M

2014-01-01

Animal models are valuable tools in fertility research. Worldwide, there are more than 400 transgenic or knockout mouse models available showing a reproductive phenotype; almost all of them exhibit an infertile or at least subfertile phenotype. By contrast, animal models revealing an improved fertility phenotype are barely described. This article summarizes data on two outbred mouse models exhibiting a 'high-fertility' phenotype. These mouse lines were generated via selection over a time period of more than 40 years and 161 generations. During this selection period, the number of offspring per litter and the total birth weight of the entire litter nearly doubled. Concomitantly with the increased fertility phenotype, several endocrine parameters (e.g. serum testosterone concentrations in male animals), physiological parameters (e.g. body weight, accelerated puberty, and life expectancy), and behavioral parameters (e.g. behavior in an open field and endurance fitness on a treadmill) were altered. We demonstrate that the two independently bred high-fertility mouse lines warranted their improved fertility phenotype using different molecular and physiological strategies. The fertility lines display female- as well as male-specific characteristics. These genetically heterogeneous mouse models provide new insights into molecular and cellular mechanisms that enhance fertility. In view of decreasing fertility in men, these models will therefore be a precious information source for human reproductive medicine. Translated abstract A German translation of abstract is freely available at http://www.reproduction-online.org/content/147/4/427/suppl/DC1.

Ultrasonic vocalizations: a tool for behavioural phenotyping of mouse models of neurodevelopmental disorders

PubMed Central

Scattoni, Maria Luisa; Crawley, Jacqueline; Ricceri, Laura

2009-01-01

In neonatal mice ultrasonic vocalizations have been studied both as an early communicative behavior of the pup-mother dyad and as a sign of an aversive affective state. Adult mice of both sexes produce complex ultrasonic vocalization patterns in different experimental/social contexts. All these vocalizations are becoming an increasingly valuable assay for behavioral phenotyping throughout the mouse life-span and alterations of the ultrasound patterns have been reported in several mouse models of neurodevelopmental disorders. Here we also show that the modulation of vocalizations by maternal cues (maternal potentiation paradigm) – originally identified and investigated in rats - can be measured in C57Bl/6 mouse pups with appropriate modifications of the rat protocol and can likely be applied to mouse behavioral phenotyping. In addition we suggest that a detailed qualitative evaluation of neonatal calls together with analysis of adult mouse vocalization patterns in both sexes in social settings, may lead to a greater understanding of the communication value of vocalizations in mice. Importantly, both neonatal and adult USV altered patterns can be determined during the behavioural phenotyping of mouse models of human neurodevelopmental and neuropsychiatric disorders, starting from those in which deficits in communication are a primary symptom. PMID:18771687

Inferring duplications, losses, transfers and incomplete lineage sorting with nonbinary species trees.

PubMed

Stolzer, Maureen; Lai, Han; Xu, Minli; Sathaye, Deepa; Vernot, Benjamin; Durand, Dannie

2012-09-15

Gene duplication (D), transfer (T), loss (L) and incomplete lineage sorting (I) are crucial to the evolution of gene families and the emergence of novel functions. The history of these events can be inferred via comparison of gene and species trees, a process called reconciliation, yet current reconciliation algorithms model only a subset of these evolutionary processes. We present an algorithm to reconcile a binary gene tree with a nonbinary species tree under a DTLI parsimony criterion. This is the first reconciliation algorithm to capture all four evolutionary processes driving tree incongruence and the first to reconcile non-binary species trees with a transfer model. Our algorithm infers all optimal solutions and reports complete, temporally feasible event histories, giving the gene and species lineages in which each event occurred. It is fixed-parameter tractable, with polytime complexity when the maximum species outdegree is fixed. Application of our algorithms to prokaryotic and eukaryotic data show that use of an incomplete event model has substantial impact on the events inferred and resulting biological conclusions. Our algorithms have been implemented in Notung, a freely available phylogenetic reconciliation software package, available at http://www.cs.cmu.edu/~durand/Notung. mstolzer@andrew.cmu.edu.

Nucleic Acid Chaperone Activity of the ORF1 Protein from the Mouse LINE-1 Retrotransposon

PubMed Central

Martin, Sandra L.; Bushman, Frederic D.

2001-01-01

Non-LTR retrotransposons such as L1 elements are major components of the mammalian genome, but their mechanism of replication is incompletely understood. Like retroviruses and LTR-containing retrotransposons, non-LTR retrotransposons replicate by reverse transcription of an RNA intermediate. The details of cDNA priming and integration, however, differ between these two classes. In retroviruses, the nucleocapsid (NC) protein has been shown to assist reverse transcription by acting as a “nucleic acid chaperone,” promoting the formation of the most stable duplexes between nucleic acid molecules. A protein-coding region with an NC-like sequence is present in most non-LTR retrotransposons, but no such sequence is evident in mammalian L1 elements or other members of its class. Here we investigated the ORF1 protein from mouse L1 and found that it does in fact display nucleic acid chaperone activities in vitro. L1 ORF1p (i) promoted annealing of complementary DNA strands, (ii) facilitated strand exchange to form the most stable hybrids in competitive displacement assays, and (iii) facilitated melting of an imperfect duplex but stabilized perfect duplexes. These findings suggest a role for L1 ORF1p in mediating nucleic acid strand transfer steps during L1 reverse transcription. PMID:11134335

Reduced endothelin converting enzyme-1 and endothelin-3 mRNA in the developing bowel of male mice may increase expressivity and penetrance of Hirschsprung disease-like distal intestinal aganglionosis.

PubMed

Vohra, Bhupinder P S; Planer, William; Armon, Jennifer; Fu, Ming; Jain, Sanjay; Heuckeroth, Robert O

2007-01-01

Hirschsprung disease (distal intestinal aganglionosis, HSCR) is a multigenic disorder with incomplete penetrance, variable expressivity, and a strong male gender bias. Recent studies demonstrated that these genetic patterns arise because gene interactions determine whether enteric nervous system (ENS) precursors successfully proliferate and migrate into the distal bowel. We now demonstrate that male gender bias in the extent of distal intestinal aganglionosis occurs in mice with Ret dominant-negative mutations (RetDN) that mimic human HSCR. We hypothesized that male gender bias could result from reduced expression of a gene already known to be essential for ENS development. Using quantitative real-time polymerase chain reaction (PCR) we demonstrated reduced levels of endothelin converting enzyme-1 and endothelin-3 mRNA in the male mouse bowel at the time that ENS precursors migrate into the colon. Other HSCR-associated genes are expressed at comparable levels in male and female mice. Testosterone and Mullerian inhibiting substance had no deleterious effect on ENS precursor development, but adding EDN3 peptide to E11.5 male RetDN heterozygous mouse gut explants in organ culture significantly increased the rate of ENS precursor migration through the bowel.

Genomic and chromatin features shaping meiotic double-strand break formation and repair in mice

PubMed Central

Jasin, Maria; Lange, Julian

2017-01-01

ABSTRACT The SPO11-generated DNA double-strand breaks (DSBs) that initiate meiotic recombination occur non-randomly across genomes, but mechanisms shaping their distribution and repair remain incompletely understood. Here, we expand on recent studies of nucleotide-resolution DSB maps in mouse spermatocytes. We find that trimethylation of histone H3 lysine 36 around DSB hotspots is highly correlated, both spatially and quantitatively, with trimethylation of H3 lysine 4, consistent with coordinated formation and action of both PRDM9-dependent histone modifications. In contrast, the DSB-responsive kinase ATM contributes independently of PRDM9 to controlling hotspot activity, and combined action of ATM and PRDM9 can explain nearly two-thirds of the variation in DSB frequency between hotspots. DSBs were modestly underrepresented in most repetitive sequences such as segmental duplications and transposons. Nonetheless, numerous DSBs form within repetitive sequences in each meiosis and some classes of repeats are preferentially targeted. Implications of these findings are discussed for evolution of PRDM9 and its role in hybrid strain sterility in mice. Finally, we document the relationship between mouse strain-specific DNA sequence variants within PRDM9 recognition motifs and attendant differences in recombination outcomes. Our results provide further insights into the complex web of factors that influence meiotic recombination patterns. PMID:28820351

Integrative Analysis of Sex-Specific microRNA Networks Following Stress in Mouse Nucleus Accumbens.

PubMed

Pfau, Madeline L; Purushothaman, Immanuel; Feng, Jian; Golden, Sam A; Aleyasin, Hossein; Lorsch, Zachary S; Cates, Hannah M; Flanigan, Meghan E; Menard, Caroline; Heshmati, Mitra; Wang, Zichen; Ma'ayan, Avi; Shen, Li; Hodes, Georgia E; Russo, Scott J

2016-01-01

Adult women are twice as likely as men to suffer from affective and anxiety disorders, although the mechanisms underlying heightened female stress susceptibility are incompletely understood. Recent findings in mouse Nucleus Accumbens (NAc) suggest a role for DNA methylation-driven sex differences in genome-wide transcriptional profiles. However, the role of another epigenetic process-microRNA (miR) regulation-has yet to be explored. We exposed male and female mice to Subchronic Variable Stress (SCVS), a stress paradigm that produces depression-like behavior in female, but not male, mice, and performed next generation mRNA and miR sequencing on NAc tissue. We applied a combination of differential expression, miR-mRNA network and functional enrichment analyses to characterize the transcriptional and post-transcriptional landscape of sex differences in NAc stress response. We find that male and female mice exhibit largely non-overlapping miR and mRNA profiles following SCVS. The two sexes also show enrichment of different molecular pathways and functions. Collectively, our results suggest that males and females mount fundamentally different transcriptional and post-transcriptional responses to SCVS and engage sex-specific molecular processes following stress. These findings have implications for the pathophysiology and treatment of stress-related disorders in women.

A Comparison of Some Organizational Characteristics of the Mouse Central Retina and the Human Macula

PubMed Central

Hoo, Juyea; Yee, Claudine; Williams, David S.

2015-01-01

Mouse models have greatly assisted our understanding of retinal degenerations. However, the mouse retina does not have a macula, leading to the question of whether the mouse is a relevant model for macular degeneration. In the present study, a quantitative comparison between the organization of the central mouse retina and the human macula was made, focusing on some structural characteristics that have been suggested to be important in predisposing the macula to stresses leading to degeneration: photoreceptor density, phagocytic load on the RPE, and the relative thinness of Bruch’s membrane. Light and electron microscopy measurements from retinas of two strains of mice, together with published data on human retinas, were used for calculations and subsequent comparisons. As in the human retina, the central region of the mouse retina possesses a higher photoreceptor cell density and a thinner Bruch’s membrane than in the periphery; however, the magnitudes of these periphery to center gradients are larger in the human. Of potentially greater relevance is the actual photoreceptor cell density, which is much greater in the mouse central retina than in the human macula, underlying a higher phagocytic load for the mouse RPE. Moreover, at eccentricities that correspond to the peripheral half of the human macula, the rod to cone ratio is similar between mouse and human. Hence, with respect to photoreceptor density and phagocytic load of the RPE, the central mouse retina models at least the more peripheral part of the macula, where macular degeneration is often first evident. PMID:25923208

Cloned ferrets produced by somatic cell nuclear transfer.

PubMed

Li, Ziyi; Sun, Xingshen; Chen, Juan; Liu, Xiaoming; Wisely, Samantha M; Zhou, Qi; Renard, Jean-Paul; Leno, Gregory H; Engelhardt, John F

2006-05-15

Somatic cell nuclear transfer (SCNT) offers great potential for developing better animal models of human disease. The domestic ferret (Mustela putorius furo) is an ideal animal model for influenza infections and potentially other human respiratory diseases such as cystic fibrosis, where mouse models have failed to reproduce the human disease phenotype. Here, we report the successful production of live cloned, reproductively competent, ferrets using species-specific SCNT methodologies. Critical to developing a successful SCNT protocol for the ferret was the finding that hormonal treatment, normally used for superovulation, adversely affected the developmental potential of recipient oocytes. The onset of Oct4 expression was delayed and incomplete in parthenogenetically activated oocytes collected from hormone-treated females relative to oocytes collected from females naturally mated with vasectomized males. Stimulation induced by mating and in vitro oocyte maturation produced the optimal oocyte recipient for SCNT. Although nuclear injection and cell fusion produced mid-term fetuses at equivalent rates (approximately 3-4%), only cell fusion gave rise to healthy surviving clones. Single cell fusion rates and the efficiency of SCNT were also enhanced by placing two somatic cells into the perivitelline space. These species-specific modifications facilitated the birth of live, healthy, and fertile cloned ferrets. The development of microsatellite genotyping for domestic ferrets confirmed that ferret clones were genetically derived from their respective somatic cells and unrelated to their surrogate mother. With this technology, it is now feasible to begin generating genetically defined ferrets for studying transmissible and inherited human lung diseases. Cloning of the domestic ferret may also aid in recovery and conservation of the endangered black-footed ferret and European mink.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ding, Ying; Adachi, Hiroaki, E-mail: hadachi-ns@umin.org; Department of Neurology, University of Occupational and Environmental Health School of Medicine, 1-1 Iseigaoka, Yahata-nishi-ku, Kitakyushu 807-8555

Spinal and bulbar muscular atrophy (SBMA) is an inherited motor neuron disease caused by the expansion of a polyglutamine (polyQ)-encoding tract within the androgen receptor (AR) gene. The pathologic features of SBMA are motor neuron loss in the spinal cord and brainstem and diffuse nuclear accumulation and nuclear inclusions of mutant AR in residual motor neurons and certain visceral organs. Hepatocyte growth factor (HGF) is a polypeptide growth factor which has neuroprotective properties. To investigate whether HGF overexpression can affect disease progression in a mouse model of SBMA, we crossed SBMA transgenic model mice expressing an AR gene with anmore » expanded CAG repeat with mice overexpressing HGF. Here, we report that high expression of HGF induces Akt phosphorylation and modestly ameliorated motor symptoms in an SBMA transgenic mouse model treated with or without castration. These findings suggest that HGF overexpression can provide a potential therapeutic avenue as a combination therapy with disease-modifying therapies in SBMA. - Highlights: • HGF overexpression ameliorates the motor phenotypes of the SBMA mouse model. • HGF overexpression induces Akt phosphorylation in the SBMA mouse model. • This is the first report of combination therapy in a mouse model of polyQ diseases.« less

Defining the optimal animal model for translational research using gene set enrichment analysis.

PubMed

Weidner, Christopher; Steinfath, Matthias; Opitz, Elisa; Oelgeschläger, Michael; Schönfelder, Gilbert

2016-08-01

The mouse is the main model organism used to study the functions of human genes because most biological processes in the mouse are highly conserved in humans. Recent reports that compared identical transcriptomic datasets of human inflammatory diseases with datasets from mouse models using traditional gene-to-gene comparison techniques resulted in contradictory conclusions regarding the relevance of animal models for translational research. To reduce susceptibility to biased interpretation, all genes of interest for the biological question under investigation should be considered. Thus, standardized approaches for systematic data analysis are needed. We analyzed the same datasets using gene set enrichment analysis focusing on pathways assigned to inflammatory processes in either humans or mice. The analyses revealed a moderate overlap between all human and mouse datasets, with average positive and negative predictive values of 48 and 57% significant correlations. Subgroups of the septic mouse models (i.e., Staphylococcus aureus injection) correlated very well with most human studies. These findings support the applicability of targeted strategies to identify the optimal animal model and protocol to improve the success of translational research. © 2016 The Authors. Published under the terms of the CC BY 4.0 license.

Transgenic and gene knockout mice in gastric cancer research

PubMed Central

Jiang, Yannan; Yu, Yingyan

2017-01-01

Mouse models are useful tool for carcinogenic study. They will greatly enrich the understanding of pathogenesis and molecular mechanisms for gastric cancer. However, only few of mice could develop gastric cancer spontaneously. With the development and improvement of gene transfer technology, investigators created a variety of transgenic and knockout/knockin mouse models of gastric cancer, such as INS-GAS mice and gastrin knockout mice. Combined with helicobacter infection and carcinogens treatment, these transgenic/knockout/knockin mice developed precancerous or cancerous lesions, which are proper for gene function study or experimental therapy. Here we review the progression of genetically engineered mouse models on gastric cancer research, and emphasize the effects of chemical carcinogens or infectious factors on carcinogenesis of genetically modified mouse. We also emphasize the histological examination on mouse stomach. We expect to provide researchers with some inspirations on this field. PMID:27713138

A Mouse Model to Investigate Postmenopausal Biology as an Etiology of Ovarian Cancer Risk

DTIC Science & Technology

2006-11-01

Wv mice and genetic alterations such as p53, pten, or p27kip1, which are found in human ovarian cancer. 2. Body: Research Progress In the first year...press (Yang et al., Am. J. Pathology 2007). To collaborate with the mouse model study, we have also examined human ovaries obtained from prophylactic...results in the coming years. Xu, Xiangxi, Ph.D. 8 3. Key Research Accomplishments (1) Further verify the relevance of the Wv mouse model to human

The Oncogenic Role of RhoGAPs in Basal-Like Breast Cancer

DTIC Science & Technology

2015-02-01

cell lines, and mouse models . c) In vivo tumorigenesis and metastasis assays. Milestones: Identify whether ArhGAP11A and RacGAP1 can promote tumor growth...also upregulated in basal (C3(I)-Tag) but not luminal (MMTV-Neu) genetically- engineered mouse models (Fig. 1B). At the protein level, RacGAP1 was...hypothesis that these RhoGAPs are indeed playing an oncogenic role in these cells. Human Tumors Mouse Model Tumors Normal Luminal A Basal-like Normal

Increased thrombin generation in a mouse model of cancer cachexia is partially interleukin-6 dependent.

PubMed

Reddel, C J; Allen, J D; Ehteda, A; Taylor, R; Chen, V M Y; Curnow, J L; Kritharides, L; Robertson, G

2017-03-01

Essentials Cancer cachexia and cancer-associated thrombosis have not previously been mechanistically linked. We assessed thrombin generation and coagulation parameters in cachectic C26 tumor-bearing mice. C26 mice are hypercoagulable, partially corrected by blocking tumor derived interleukin-6. Coagulability and anti-inflammatory interventions may be clinically important in cancer cachexia. Background Cancer cachexia and cancer-associated thrombosis are potentially fatal outcomes of advanced cancer, which have not previously been mechanistically linked. The colon 26 (C26) carcinoma is a well-established mouse model of complications of advanced cancer cachexia, partially dependent on high levels of interleukin-6 (IL-6) produced by the tumor. Objectives To assess if cancer cachexia altered the coagulation state and if this was attributable to tumor IL-6 production. Methods In male BALB/c*DBA2 (F1 hybrid) mice with a C26 tumor we used modified calibrated automated thrombogram and fibrin generation (based on overall hemostatic potential) assays to assess the functional coagulation state, and also examined fibrinogen, erythrocyte sedimentation rate (ESR), platelet count, tissue factor pathway inhibitor (TFPI) and hepatic expression of coagulation factors by microarray. C26 mice were compared with non-cachectic NC26, pair-fed and sham control mice. IL-6 expression in C26 cells was knocked down by lentiviral shRNA constructs. Results C26 mice with significant weight loss and highly elevated IL-6 had elevated thrombin generation, fibrinogen, ESR, platelets and TFPI compared with all control groups. Fibrin generation was elevated compared with pair-fed and sham controls but not compared with NC26 tumor mice. Hepatic expression of coagulation factors and fibrinolytic inhibitors was increased. Silencing IL-6 in the tumor significantly, but incompletely, attenuated the increased thrombin generation, fibrinogen and TFPI. Conclusions Cachectic C26 tumor-bearing mice are in a hypercoagulable state, which is partly attributable to IL-6 release by the tumor. The findings support the importance of the coagulation state in cancer cachexia and the clinical utility of anti-inflammatory interventions. © 2017 International Society on Thrombosis and Haemostasis.

A Physiologically Based Kinetic Model of Rat and Mouse Gestation: Disposition of a Weak Acid

EPA Science Inventory

A physiologically based toxicokinetic model of gestation in the rat mouse has been developed. The model is superimposed on the normal growth curve for nonpregnant females. It describes the entire gestation period including organogenesis. The model consists of uterus, mammary tiss...

Priceless GEMMs: genetically engineered mouse models for colorectal cancer drug development.

PubMed

Roper, Jatin; Hung, Kenneth E

2012-08-01

To establish effective drug development for colorectal cancer (CRC), preclinical models that are robust surrogates for human disease are crucial. Mouse models are an attractive platform because of their relatively low cost, short life span, and ease of use. There are two main categories of mouse CRC models: xenografts derived from implantation of CRC cells or tumors in immunodeficient mice; and genetically engineered mouse models (GEMMs) derived from modification of human cancer predisposition genes, resulting in spontaneous tumor formation. Here, we review xenografts and GEMMs and focus on their potential application in translational research. Furthermore, we describe newer GEMMs for sporadic CRC that are particularly suitable for drug testing. Finally, we discuss recent advances in small-animal imaging, such as optical colonoscopy, which allow in vivo assessment of tumors. With the increasing sophistication of GEMMs, our preclinical armamentarium provides new hope for the ongoing war against CRC. Copyright © 2012. Published by Elsevier Ltd.

A Genetically Engineered Mouse Model of Sporadic Colorectal Cancer.

PubMed

Betzler, Alexander M; Kochall, Susan; Blickensdörfer, Linda; Garcia, Sebastian A; Thepkaysone, May-Linn; Nanduri, Lahiri K; Muders, Michael H; Weitz, Jürgen; Reissfelder, Christoph; Schölch, Sebastian

2017-07-06

Despite the advantages of easy applicability and cost-effectiveness, colorectal cancer mouse models based on tumor cell injection have severe limitations and do not accurately simulate tumor biology and tumor cell dissemination. Genetically engineered mouse models have been introduced to overcome these limitations; however, such models are technically demanding, especially in large organs such as the colon in which only a single tumor is desired. As a result, an immunocompetent, genetically engineered mouse model of colorectal cancer was developed which develops highly uniform tumors and can be used for tumor biology studies as well as therapeutic trials. Tumor development is initiated by surgical, segmental infection of the distal colon with adeno-cre virus in compound conditionally mutant mice. The tumors can be easily detected and monitored via colonoscopy. We here describe the surgical technique of segmental adeno-cre infection of the colon, the surveillance of the tumor via high-resolution colonoscopy and present the resulting colorectal tumors.

Studies of a Latent Class Signal Detection Model for Constructed Response Scoring II: Incomplete and Hierarchical Designs. Research Report. ETS RR-10-08

ERIC Educational Resources Information Center

DeCarlo, Lawrence T.

2010-01-01

A basic consideration in large-scale assessments that use constructed response (CR) items, such as essays, is how to allocate the essays to the raters that score them. Designs that are used in practice are incomplete, in that each essay is scored by only a subset of the raters, and also unbalanced, in that the number of essays scored by each rater…

Absence of Prenatal Forebrain Defects in the Dp(16)1Yey/+ Mouse Model of Down Syndrome

PubMed Central

Goodliffe, Joseph W.; Olmos-Serrano, Jose Luis; Aziz, Nadine M.; Pennings, Jeroen L.A.; Guedj, Faycal; Bianchi, Diana W.

2016-01-01

Studies in humans with Down syndrome (DS) show that alterations in fetal brain development are followed by postnatal deficits in neuronal numbers, synaptic plasticity, and cognitive and motor function. This same progression is replicated in several mouse models of DS. Dp(16)1Yey/+ (hereafter called Dp16) is a recently developed mouse model of DS in which the entire region of mouse chromosome 16 that is homologous to human chromosome 21 has been triplicated. As such, Dp16 mice may more closely reproduce neurodevelopmental changes occurring in humans with DS. Here, we present the first comprehensive cellular and behavioral study of the Dp16 forebrain from embryonic to adult stages. Unexpectedly, our results demonstrate that Dp16 mice do not have prenatal brain defects previously reported in human fetal neocortex and in the developing forebrains of other mouse models, including microcephaly, reduced neurogenesis, and abnormal cell proliferation. Nevertheless, we found impairments in postnatal developmental milestones, fewer inhibitory forebrain neurons, and deficits in motor and cognitive performance in Dp16 mice. Therefore, although this new model does not express prenatal morphological phenotypes associated with DS, abnormalities in the postnatal period appear sufficient to produce significant cognitive deficits in Dp16. SIGNIFICANCE STATEMENT Down syndrome (DS) leads to intellectual disability. Several mouse models have increased our understanding of the neuropathology of DS and are currently being used to test therapeutic strategies. A new mouse model that contains an expanded number of DS-related genes, known as Dp(16)1Yey/+ (Dp16), has been generated recently. We sought to determine whether the extended triplication creates a better phenocopy of DS-related brain pathologies. We measured embryonic development, forebrain maturation, and perinatal/adult behavior and revealed an absence of prenatal phenotypes in Dp16 fetal brain, but specific cellular and behavioral deficits after the first 2 postnatal weeks. These results uncover important differences in prenatal phenotype between Dp16 animals and humans with DS and other DS mouse models. PMID:26961948

Use of a highly sensitive strand-specific quantitative PCR to identify abortive replication in the mouse model of respiratory syncytial virus disease

PubMed Central

2010-01-01

Background The BALB/c mouse is commonly used to study RSV infection and disease. However, despite the many advantages of this well-characterised model, the inoculum is large, viral replication is restricted and only a very small amount of virus can be recovered from infected animals. A key question in this model is the fate of the administered virus. Is replication really being measured or is the model measuring the survival of the virus over time? To answer these questions we developed a highly sensitive strand-specific quantitative PCR (QPCR) able to accurately quantify the amount of RSV replication in the BALB/c mouse lung, allowing characterisation of RSV negative and positive strand RNA dynamics. Results In the mouse lung, no increase in RSV genome was seen above the background of the original inoculum whilst only a limited transient increase (< 1 log) in positive strand, replicative intermediate (RI) RNA occurred. This RNA did however persist at detectable levels for 59 days post infection. As expected, ribavirin therapy reduced levels of infectious virus and RI RNA in the mouse lung. However, whilst Palivizumab therapy was also able to reduce levels of infectious virus, it failed to prevent production of intracellular RI RNA. A comparison of RSV RNA kinetics in human (A549) and mouse (KLN205) cell lines demonstrated that RSV replication was also severely delayed and impaired in vitro in the mouse cells. Conclusions This is the first time that such a sensitive strand-specific QPCR technique has been to the RSV mouse system. We have accurately quantified the restricted and abortive nature of RSV replication in the mouse. Further in vitro studies in human and mouse cells suggest this restricted replication is due at least in part to species-specific host cell-viral interactions. PMID:20860795

Establishment of mouse neuron and microglial cell co-cultured models and its action mechanism.

PubMed

Zhang, Bo; Yang, Yunfeng; Tang, Jun; Tao, Yihao; Jiang, Bing; Chen, Zhi; Feng, Hua; Yang, Liming; Zhu, Gang

2017-06-27

The objective of this study is to establish a co-culture model of mouse neurons and microglial cells, and to analyze the mechanism of action of oxygen glucose deprivation (OGD) and transient oxygen glucose deprivation (tOGD) preconditioning cell models. Mouse primary neurons and BV2 microglial cells were successfully cultured, and the OGD and tOGD models were also established. In the co-culture of mouse primary neurons and microglial cells, the cell number of tOGD mouse neurons and microglial cells was larger than the OGD cell number, observed by a microscope. CCK-8 assay result showed that at 1h after treatment, the OD value in the control group is lower compared to all the other three groups (P < 0.05). The treatment group exhibited the highest OD value among the four groups. The results observed at 5h were consistent with the results at 1 h. Flow cytometry results showed that at 1h after treatment the apoptosis percentages is higher in the control group compared to other three groups (P < 0.05). Mouse brain tissues were collected and primary neurons cells were cultured. In the meantime mouse BV2 microglia cells were cultured. Two types of cells were co-cultured, and OGD and tOGD cell models were established. There were four groups in the experiment: control group (OGD), treatment group (tOGD+OGD), placebo group (tOGD+OGD+saline) and minocycline intervention group (tOGD+OGD+minocycline). CCK-8 kit was used to detect cell viability and flow cytometry was used to detect apoptosis. In this study, mouse primary neurons and microglial cells were co-cultured. The OGD and tOGD models were established successfully. tOGD was able to effectively protect neurons and microglial cells from damage, and inhibit the apoptosis caused by oxygen glucose deprivation.

Transmission and adaptation of chronic wasting disease to hamsters and transgenic mice: evidence for strains.

PubMed

Raymond, Gregory J; Raymond, Lynne D; Meade-White, Kimberly D; Hughson, Andrew G; Favara, Cynthia; Gardner, Donald; Williams, Elizabeth S; Miller, Michael W; Race, Richard E; Caughey, Byron

2007-04-01

In vitro screening using the cell-free prion protein conversion system indicated that certain rodents may be susceptible to chronic wasting disease (CWD). Therefore, CWD isolates from mule deer, white-tailed deer, and elk were inoculated intracerebrally into various rodent species to assess the rodents' susceptibility and to develop new rodent models of CWD. The species inoculated were Syrian golden, Djungarian, Chinese, Siberian, and Armenian hamsters, transgenic mice expressing the Syrian golden hamster prion protein, and RML Swiss and C57BL10 wild-type mice. The transgenic mice and the Syrian golden, Chinese, Siberian, and Armenian hamsters had limited susceptibility to certain of the CWD inocula, as evidenced by incomplete attack rates and long incubation periods. For serial passages of CWD isolates in Syrian golden hamsters, incubation periods rapidly stabilized, with isolates having either short (85 to 89 days) or long (408 to 544 days) mean incubation periods and distinct neuropathological patterns. In contrast, wild-type mouse strains and Djungarian hamsters were not susceptible to CWD. These results show that CWD can be transmitted and adapted to some species of rodents and suggest that the cervid-derived CWD inocula may have contained or diverged into at least two distinct transmissible spongiform encephalopathy strains.

LKB1 loss promotes endometrial cancer progression via CCL2-dependent macrophage recruitment.

PubMed

Peña, Christopher G; Nakada, Yuji; Saatcioglu, Hatice D; Aloisio, Gina M; Cuevas, Ileana; Zhang, Song; Miller, David S; Lea, Jayanthi S; Wong, Kwok-Kin; DeBerardinis, Ralph J; Amelio, Antonio L; Brekken, Rolf A; Castrillon, Diego H

2015-11-02

Endometrial cancer is the most common gynecologic malignancy and the fourth most common malignancy in women. For most patients in whom the disease is confined to the uterus, treatment results in successful remission; however, there are no curative treatments for tumors that have progressed beyond the uterus. The serine/threonine kinase LKB1 has been identified as a potent suppressor of uterine cancer, but the biological modes of action of LKB1 in this context remain incompletely understood. Here, we have shown that LKB1 suppresses tumor progression by altering gene expression in the tumor microenvironment. We determined that LKB1 inactivation results in abnormal, cell-autonomous production of the inflammatory cytokine chemokine (C-C motif) ligand 2 (CCL2) within tumors, which leads to increased recruitment of macrophages with prominent tumor-promoting activities. Inactivation of Ccl2 in an Lkb1-driven mouse model of endometrial cancer slowed tumor progression and increased survival. In human primary endometrial cancers, loss of LKB1 protein was strongly associated with increased CCL2 expression by tumor cells as well as increased macrophage density in the tumor microenvironment. These data demonstrate that CCL2 is a potent effector of LKB1 loss in endometrial cancer, creating potential avenues for therapeutic opportunities.

Regulator of calcineurin 1 mediates pathological vascular wall remodeling

PubMed Central

Esteban, Vanesa; Méndez-Barbero, Nerea; Jesús Jiménez-Borreguero, Luis; Roqué, Mercè; Novensá, Laura; Belén García-Redondo, Ana; Salaices, Mercedes; Vila, Luis; Arbonés, María L.

2011-01-01

Artery wall remodeling, a major feature of diseases such as hypertension, restenosis, atherosclerosis, and aneurysm, involves changes in the tunica media mass that reduce or increase the vessel lumen. The identification of molecules involved in vessel remodeling could aid the development of improved treatments for these pathologies. Angiotensin II (AngII) is a key effector of aortic wall remodeling that contributes to aneurysm formation and restenosis through incompletely defined signaling pathways. We show that AngII induces vascular smooth muscle cell (VSMC) migration and vessel remodeling in mouse models of restenosis and aneurysm. These effects were prevented by pharmacological inhibition of calcineurin (CN) or lentiviral delivery of CN-inhibitory peptides. Whole-genome analysis revealed >1,500 AngII-regulated genes in VSMCs, with just 11 of them requiring CN activation. Of these, the most sensitive to CN activation was regulator of CN 1 (Rcan1). Rcan1 was strongly activated by AngII in vitro and in vivo and was required for AngII-induced VSMC migration. Remarkably, Rcan1−/− mice were resistant to AngII-induced aneurysm and restenosis. Our results indicate that aneurysm formation and restenosis share mechanistic elements and identify Rcan1 as a potential therapeutic target for prevention of aneurysm and restenosis progression. PMID:21930771

A kinetic investigation of interacting, stimulated T cells identifies conditions for rapid functional enhancement, minimal phenotype differentiation, and improved adoptive cell transfer tumor eradication.

PubMed

Zhou, Jing; Bethune, Michael T; Malkova, Natalia; Sutherland, Alexander M; Comin-Anduix, Begonya; Su, Yapeng; Baltimore, David; Ribas, Antoni; Heath, James R

2018-01-01

For adoptive cell transfer (ACT) immunotherapy of tumor-reactive T cells, an effective therapeutic outcome depends upon cell dose, cell expansion in vivo through a minimally differentiated phenotype, long term persistence, and strong cytolytic effector function. An incomplete understanding of the biological coupling between T cell expansion, differentiation, and response to stimulation hinders the co-optimization of these factors. We report on a biophysical investigation of how the short-term kinetics of T cell functional activation, through molecular stimulation and cell-cell interactions, competes with phenotype differentiation. T cells receive molecular stimulation for a few minutes to a few hours in bulk culture. Following this priming period, the cells are then analyzed at the transcriptional level, or isolated as single cells, with continuing molecular stimulation, within microchambers for analysis via 11-plex secreted protein assays. We resolve a rapid feedback mechanism, promoted by T cell-T cell contact interactions, which strongly amplifies T cell functional performance while yielding only minimal phenotype differentiation. When tested in mouse models of ACT, optimally primed T cells lead to complete tumor eradication. A similar kinetic process is identified in CD8+ and CD4+ T cells collected from a patient with metastatic melanoma.

A kinetic investigation of interacting, stimulated T cells identifies conditions for rapid functional enhancement, minimal phenotype differentiation, and improved adoptive cell transfer tumor eradication

PubMed Central

Zhou, Jing; Bethune, Michael T.; Malkova, Natalia; Sutherland, Alexander M.; Comin-Anduix, Begonya; Su, Yapeng; Baltimore, David; Ribas, Antoni

2018-01-01

For adoptive cell transfer (ACT) immunotherapy of tumor-reactive T cells, an effective therapeutic outcome depends upon cell dose, cell expansion in vivo through a minimally differentiated phenotype, long term persistence, and strong cytolytic effector function. An incomplete understanding of the biological coupling between T cell expansion, differentiation, and response to stimulation hinders the co-optimization of these factors. We report on a biophysical investigation of how the short-term kinetics of T cell functional activation, through molecular stimulation and cell-cell interactions, competes with phenotype differentiation. T cells receive molecular stimulation for a few minutes to a few hours in bulk culture. Following this priming period, the cells are then analyzed at the transcriptional level, or isolated as single cells, with continuing molecular stimulation, within microchambers for analysis via 11-plex secreted protein assays. We resolve a rapid feedback mechanism, promoted by T cell—T cell contact interactions, which strongly amplifies T cell functional performance while yielding only minimal phenotype differentiation. When tested in mouse models of ACT, optimally primed T cells lead to complete tumor eradication. A similar kinetic process is identified in CD8+ and CD4+ T cells collected from a patient with metastatic melanoma. PMID:29360859

Notch signaling inhibits hepatocellular carcinoma following inactivation of the RB pathway

PubMed Central

Viatour, Patrick; Ehmer, Ursula; Saddic, Louis A.; Dorrell, Craig; Andersen, Jesper B.; Lin, Chenwei; Zmoos, Anne-Flore; Mazur, Pawel K.; Schaffer, Bethany E.; Ostermeier, Austin; Vogel, Hannes; Sylvester, Karl G.; Thorgeirsson, Snorri S.; Grompe, Markus

2011-01-01

Hepatocellular carcinoma (HCC) is the third cancer killer worldwide with >600,000 deaths every year. Although the major risk factors are known, therapeutic options in patients remain limited in part because of our incomplete understanding of the cellular and molecular mechanisms influencing HCC development. Evidence indicates that the retinoblastoma (RB) pathway is functionally inactivated in most cases of HCC by genetic, epigenetic, and/or viral mechanisms. To investigate the functional relevance of this observation, we inactivated the RB pathway in the liver of adult mice by deleting the three members of the Rb (Rb1) gene family: Rb, p107, and p130. Rb family triple knockout mice develop liver tumors with histopathological features and gene expression profiles similar to human HCC. In this mouse model, cancer initiation is associated with the specific expansion of populations of liver stem/progenitor cells, indicating that the RB pathway may prevent HCC development by maintaining the quiescence of adult liver progenitor cells. In addition, we show that during tumor progression, activation of the Notch pathway via E2F transcription factors serves as a negative feedback mechanism to slow HCC growth. The level of Notch activity is also able to predict survival of HCC patients, suggesting novel means to diagnose and treat HCC. PMID:21875955

Mechanisms of Heightened Airway Sensitivity and Responses to Inhaled SO2 in Asthmatics.

PubMed

Reno, Anita L; Brooks, Edward G; Ameredes, Bill T

2015-01-01

Sulfur dioxide (SO2) is a problematic inhalable air pollutant in areas of widespread industrialization, not only in the United States but also in countries undergoing rapid industrialization, such as China, and it can be a potential trigger factor for asthma exacerbations. It is known that asthmatics are sensitive to the effects of SO2; however, the basis of this enhanced sensitivity remains incompletely understood. A PubMed search was performed over the course of 2014, encompassing the following terms: asthma, airway inflammation, sulfur dioxide, IL-10, mouse studies, and human studies. This search indicated that biomarkers of SO2 exposure, SO2 effects on airway epithelial cell function, and animal model data are useful in our understanding of the body's response to SO2, as are SO2-associated amplification of allergic inflammation, and potential promotion of neurogenic inflammation due to chemical irritant properties. While definitive answers are still being sought, these areas comprise important foci of consideration regarding asthmatic responses to inhaled SO2. Furthermore, IL-10 deficiency associated with asthma may be another important factor associated with an inability to resolve inflammation and mitigate oxidative stress resulting from SO2 inhalation, supporting the idea that asthmatics are predisposed to SO2 sensitivity, leading to asthma exacerbations and airway dysfunction.

Mechanisms of Heightened Airway Sensitivity and Responses to Inhaled SO2 in Asthmatics

PubMed Central

Reno, Anita L; Brooks, Edward G; Ameredes, Bill T

2015-01-01

Sulfur dioxide (SO2) is a problematic inhalable air pollutant in areas of widespread industrialization, not only in the United States but also in countries undergoing rapid industrialization, such as China, and it can be a potential trigger factor for asthma exacerbations. It is known that asthmatics are sensitive to the effects of SO2; however, the basis of this enhanced sensitivity remains incompletely understood. A PubMed search was performed over the course of 2014, encompassing the following terms: asthma, airway inflammation, sulfur dioxide, IL-10, mouse studies, and human studies. This search indicated that biomarkers of SO2 exposure, SO2 effects on airway epithelial cell function, and animal model data are useful in our understanding of the body’s response to SO2, as are SO2-associated amplification of allergic inflammation, and potential promotion of neurogenic inflammation due to chemical irritant properties. While definitive answers are still being sought, these areas comprise important foci of consideration regarding asthmatic responses to inhaled SO2. Furthermore, IL-10 deficiency associated with asthma may be another important factor associated with an inability to resolve inflammation and mitigate oxidative stress resulting from SO2 inhalation, supporting the idea that asthmatics are predisposed to SO2 sensitivity, leading to asthma exacerbations and airway dysfunction. PMID:25922579

Diverse Developmental Disorders from The One Ring: Distinct Molecular Pathways Underlie the Cohesinopathies

PubMed Central

Horsfield, Julia A.; Print, Cristin G.; Mönnich, Maren

2012-01-01

The multi-subunit protein complex, cohesin, is responsible for sister chromatid cohesion during cell division. The interaction of cohesin with DNA is controlled by a number of additional regulatory proteins. Mutations in cohesin, or its regulators, cause a spectrum of human developmental syndromes known as the “cohesinopathies.” Cohesinopathy disorders include Cornelia de Lange Syndrome and Roberts Syndrome. The discovery of novel roles for chromatid cohesion proteins in regulating gene expression led to the idea that cohesinopathies are caused by dysregulation of multiple genes downstream of mutations in cohesion proteins. Consistent with this idea, Drosophila, mouse, and zebrafish cohesinopathy models all show altered expression of developmental genes. However, there appears to be incomplete overlap among dysregulated genes downstream of mutations in different components of the cohesion apparatus. This is surprising because mutations in all cohesion proteins would be predicted to affect cohesin’s roles in cell division and gene expression in similar ways. Here we review the differences and similarities between genetic pathways downstream of components of the cohesion apparatus, and discuss how such differences might arise, and contribute to the spectrum of cohesinopathy disorders. We propose that mutations in different elements of the cohesion apparatus have distinct developmental outcomes that can be explained by sometimes subtly different molecular effects. PMID:22988450

SGP-1: Prediction and Validation of Homologous Genes Based on Sequence Alignments

PubMed Central

Wiehe, Thomas; Gebauer-Jung, Steffi; Mitchell-Olds, Thomas; Guigó, Roderic

2001-01-01

Conventional methods of gene prediction rely on the recognition of DNA-sequence signals, the coding potential or the comparison of a genomic sequence with a cDNA, EST, or protein database. Reasons for limited accuracy in many circumstances are species-specific training and the incompleteness of reference databases. Lately, comparative genome analysis has attracted increasing attention. Several analysis tools that are based on human/mouse comparisons are already available. Here, we present a program for the prediction of protein-coding genes, termed SGP-1 (Syntenic Gene Prediction), which is based on the similarity of homologous genomic sequences. In contrast to most existing tools, the accuracy of SGP-1 depends little on species-specific properties such as codon usage or the nucleotide distribution. SGP-1 may therefore be applied to nonstandard model organisms in vertebrates as well as in plants, without the need for extensive parameter training. In addition to predicting genes in large-scale genomic sequences, the program may be useful to validate gene structure annotations from databases. To this end, SGP-1 output also contains comparisons between predicted and annotated gene structures in HTML format. The program can be accessed via a Web server at http://soft.ice.mpg.de/sgp-1. The source code, written in ANSI C, is available on request from the authors. PMID:11544202

Detection of microvasculature alterations by synchrotron radiation in murine with delayed jellyfish envenomation syndrome.

PubMed

Wang, Beilei; Zhang, Bo; Huo, Hua; Wang, Tao; Wang, Qianqian; Wu, Yuanlin; Xiao, Liang; Ren, Yuqi; Zhang, Liming

2014-04-01

Using the tentacle extract (TE) from the jellyfish Cyanea capillata, we have previously established a delayed jellyfish envenomation syndrome (DJES) model, which is meaningful for clinical interventions against jellyfish stings. However, the mechanism of DJES still remains unclear. Thus, this study aimed to explore its potential mechanism by detecting TE-induced microvasculature alterations in vivo and ex vivo. Using a third-generation synchrotron radiation facility, we, for the first time, directly observed the blood vessel alterations induced by jellyfish venom in vivo and ex vivo. Firstly, microvasculature imaging of whole-body mouse in vivo indicated that the small blood vessel branches in the liver and kidney in the TE-treated group, seemed much thinner than those in the control group. Secondly, 3D imaging of kidney ex vivo showed that the kidneys in the TE-treated group had incomplete vascular trees where distal vessel branches were partly missing and disorderly disturbed. Finally, histopathological analysis found that obvious morphological changes, especially hemorrhagic effects, were also present in the TE-treated kidney. Thus, TE-induced microvasculature changes might be one of the important mechanisms of multiple organ dysfunctions in DJES. In addition, the methods we employed here will probably facilitate further studies on developing effective intervention strategies against DJES. Copyright © 2014 Elsevier Ltd. All rights reserved.

The risk of hemophagocytic lymphohistiocytosis in Hermansky-Pudlak syndrome type 2

PubMed Central

Jessen, Birthe; Bode, Sebastian F. N.; Ammann, Sandra; Chakravorty, Subarna; Davies, Graham; Diestelhorst, Jana; Frei-Jones, Melissa; Gahl, William A.; Gochuico, Bernadette R.; Griese, Matthias; Griffiths, Gillian; Janka, Gritta; Klein, Christoph; Kögl, Tamara; Kurnik, Karin; Lehmberg, Kai; Maul-Pavicic, Andrea; Mumford, Andrew D.; Pace, David; Parvaneh, Nima; Rezaei, Nima; de Saint Basile, Geneviève; Schmitt-Graeff, Annette; Schwarz, Klaus; Karasu, Gulsun T.; Zieger, Barbara; zur Stadt, Udo; Aichele, Peter

2013-01-01

Genetic disorders of lymphocyte cytotoxicity predispose patients to hemophagocytic lymphohistiocytosis (HLH). Reduced lymphocyte cytotoxicity has been demonstrated in Hermansky-Pudlak syndrome type 2 (HPS2), but only a single patient was reported who developed HLH. Because that patient also carried a potentially contributing heterozygous RAB27A mutation, the risk for HLH in HPS2 remains unclear. We analyzed susceptibility to HLH in the pearl mouse model of HPS2. After infection with lymphocytic choriomeningitis virus, pearl mice developed all key features of HLH, linked to impaired virus control caused by a moderate defect in CTL cytotoxicity in vivo. However, in contrast to perforin-deficient mice, the disease was transient, and all mice fully recovered and controlled the infection. An additional heterozygous Rab27a mutation did not aggravate the cytotoxicity defect or disease parameters. In the largest survey of 22 HPS2 patients covering 234 patient years, we identified only 1 additional patient with HLH and 2 with incomplete transient HLH-like episodes, although cytotoxicity or degranulation was impaired in all 16 patients tested. HPS2 confers a risk for HLH that is lower than in Griscelli or Chediak-Higashi syndrome, probably because of a milder defect in cytotoxicity. Preemptive hematopoietic stem cell transplantation does not appear justified in HPS2. PMID:23403622

Mucus-Penetrating Nanoparticles for Vaginal Drug Delivery Protect Against Herpes Simplex Virus

PubMed Central

Ensign, Laura M.; Tang, Benjamin C.; Wang, Ying-Ying; Tse, Terence A.; Hoen, Timothy; Cone, Richard; Hanes, Justin

2013-01-01

Incomplete coverage and short duration of action limit the effectiveness of vaginally administered drugs, including microbicides for preventing sexually transmitted infections. We investigated vaginal distribution, retention, and safety of nanoparticles with surfaces modified to enhance transport through mucus. We show that mucus-penetrating particles (MPPs) provide uniform distribution over the vaginal epithelium, whereas conventional nanoparticles (CPs) that are mucoadhesive are aggregated by mouse vaginal mucus, leading to poor distribution. Moreover, when delivered hypotonically, MPPs were transported advectively (versus diffusively) through mucus deep into vaginal folds (rugae) within minutes. By penetrating into the deepest mucus layers, more MPPs were retained in the vaginal tract after 6 h compared to CPs. After 24 h, when delivered in a conventional vaginal gel, patches of a model drug remained on the vaginal epithelium, whereas the epithelium was coated with drug delivered by MPP. We then developed MPPs composed of acyclovir monophosphate (ACVp). When administered prior to vaginal herpes simplex virus 2 (HSV-2) challenge, ACVp-MPPs protected 53% of mice, compared to only 16% protected by soluble drug. Overall, MPPs improved vaginal drug distribution and retention, provided more effective protection against vaginal viral challenge than soluble drug, and were non-toxic when administered daily for one week. PMID:22700955

Stress-resistant Translation of Cathepsin L mRNA in Breast Cancer Progression*

PubMed Central

Tholen, Martina; Wolanski, Julia; Stolze, Britta; Chiabudini, Marco; Gajda, Mieczyslaw; Bronsert, Peter; Stickeler, Elmar; Rospert, Sabine; Reinheckel, Thomas

2015-01-01

The cysteine protease cathepsin L (CTSL) is often thought to act as a tumor promoter by enhancing tumor progression and metastasis. This goes along with increased CTSL activity in various tumor entities; however, the mechanisms leading to high CTSL levels are incompletely understood. With the help of the polyoma middle T oncogene driven breast cancer mouse model expressing a human CTSL genomic transgene, we show that CTSL indeed promotes breast cancer metastasis to the lung. During tumor formation and progression high expression levels of CTSL are maintained by enduring translation of CTSL mRNA. Interestingly, human breast cancer specimens expressed the same pattern of 5′ untranslated region (UTR) splice variants as the transgenic mice and the human cancer cell line MDA-MB 321. By polyribosome profiling of tumor tissues and human breast cancer cells, we observe an intrinsic resistance of CTSL to stress-induced shutdown of translation. This ability can be attributed to all 5′ UTR variants of CTSL and is not dependent on a previously described internal ribosomal entry site motif. In conclusion, we provide in vivo functional evidence for overexpressed CTSL as a promoter of lung metastasis, whereas high CTSL levels are maintained during tumor progression due to stress-resistant mRNA translation. PMID:25957406

Incomplete data based parameter identification of nonlinear and time-variant oscillators with fractional derivative elements

NASA Astrophysics Data System (ADS)

Kougioumtzoglou, Ioannis A.; dos Santos, Ketson R. M.; Comerford, Liam

2017-09-01

Various system identification techniques exist in the literature that can handle non-stationary measured time-histories, or cases of incomplete data, or address systems following a fractional calculus modeling. However, there are not many (if any) techniques that can address all three aforementioned challenges simultaneously in a consistent manner. In this paper, a novel multiple-input/single-output (MISO) system identification technique is developed for parameter identification of nonlinear and time-variant oscillators with fractional derivative terms subject to incomplete non-stationary data. The technique utilizes a representation of the nonlinear restoring forces as a set of parallel linear sub-systems. In this regard, the oscillator is transformed into an equivalent MISO system in the wavelet domain. Next, a recently developed L1-norm minimization procedure based on compressive sensing theory is applied for determining the wavelet coefficients of the available incomplete non-stationary input-output (excitation-response) data. Finally, these wavelet coefficients are utilized to determine appropriately defined time- and frequency-dependent wavelet based frequency response functions and related oscillator parameters. Several linear and nonlinear time-variant systems with fractional derivative elements are used as numerical examples to demonstrate the reliability of the technique even in cases of noise corrupted and incomplete data.

Social Interactions under Incomplete Information: Games, Equilibria, and Expectations

NASA Astrophysics Data System (ADS)

Yang, Chao

My dissertation research investigates interactions of agents' behaviors through social networks when some information is not shared publicly, focusing on solutions to a series of challenging problems in empirical research, including heterogeneous expectations and multiple equilibria. The first chapter, "Social Interactions under Incomplete Information with Heterogeneous Expectations", extends the current literature in social interactions by devising econometric models and estimation tools with private information in not only the idiosyncratic shocks but also some exogenous covariates. For example, when analyzing peer effects in class performances, it was previously assumed that all control variables, including individual IQ and SAT scores, are known to the whole class, which is unrealistic. This chapter allows such exogenous variables to be private information and models agents' behaviors as outcomes of a Bayesian Nash Equilibrium in an incomplete information game. The distribution of equilibrium outcomes can be described by the equilibrium conditional expectations, which is unique when the parameters are within a reasonable range according to the contraction mapping theorem in function spaces. The equilibrium conditional expectations are heterogeneous in both exogenous characteristics and the private information, which makes estimation in this model more demanding than in previous ones. This problem is solved in a computationally efficient way by combining the quadrature method and the nested fixed point maximum likelihood estimation. In Monte Carlo experiments, if some exogenous characteristics are private information and the model is estimated under the mis-specified hypothesis that they are known to the public, estimates will be biased. Applying this model to municipal public spending in North Carolina, significant negative correlations between contiguous municipalities are found, showing free-riding effects. The Second chapter "A Tobit Model with Social Interactions under Incomplete Information", is an application of the first chapter to censored outcomes, corresponding to the situation when agents" behaviors are subjected to some binding restrictions. In an interesting empirical analysis for property tax rates set by North Carolina municipal governments, it is found that there is a significant positive correlation among near-by municipalities. Additionally, some private information about its own residents is used by a municipal government to predict others' tax rates, which enriches current empirical work about tax competition. The third chapter, "Social Interactions under Incomplete Information with Multiple Equilibria", extends the first chapter by investigating effective estimation methods when the condition for a unique equilibrium may not be satisfied. With multiple equilibria, the previous model is incomplete due to the unobservable equilibrium selection. Neither conventional likelihoods nor moment conditions can be used to estimate parameters without further specifications. Although there are some solutions to this issue in the current literature, they are based on strong assumptions such as agents with the same observable characteristics play the same strategy. This paper relaxes those assumptions and extends the all-solution method used to estimate discrete choice games to a setting with both discrete and continuous choices, bounded and unbounded outcomes, and a general form of incomplete information, where the existence of a pure strategy equilibrium has been an open question for a long time. By the use of differential topology and functional analysis, it is found that when all exogenous characteristics are public information, there are a finite number of equilibria. With privately known exogenous characteristics, the equilbria can be represented by a compact set in a Banach space and be approximated by a finite set. As a result, a finite-state probability mass function can be used to specify a probability measure for equilibrium selection, which completes the model. From Monte Carlo experiments about two types of binary choice models, it is found that assuming equilibrium uniqueness can bring in estimation biases when the true value of interaction intensity is large and there are multiple equilibria in the data generating process.

Actinic keratosis modelling in mice: A translational study

PubMed Central

Vandenberghe, Isabelle; Cartron, Valérie; Cèbe, Patrick; Blanchet, Jean-Christophe; Sibaud, Vincent; Guilbaud, Nicolas; Audoly, Laurent; Lamant, Laurence; Kruczynski, Anna

2017-01-01

Background Actinic keratoses (AK) are pre-malignant cutaneous lesions caused by prolonged exposure to ultraviolet radiation. As AKs lesions are generally accepted to be the initial lesions in a disease continuum that progresses to squamous cell carcinoma (SCC), AK lesions have to be treated. They are also the second most common reason for visits to the dermatologist. Several treatments are available but their efficacy still needs to be improved. The UV-B-induced KA lesion mouse model is used in preclinical studies to assess the efficacy of novel molecules, even though it is often more representative of advanced AK or SCC. Objectives Here we report on a translational study, comparing the various stages of AK development in humans and in the UV-B irradiated mouse model, as well as the optimization of photograph acquisition of AK lesions on mouse skin. Methods Human and mouse skin lesions were analysed by histology and immunohistochemistry. Mouse lesions were also assessed using a digital dermatoscope. Results An histological and phenotypic analysis, including p53, Ki67 and CD3 expression detection, performed on human and mouse AK lesions, shows that overall AK modelling in mice is relevant in the clinical situation. Some differences are observed, such as disorganization of keratinocytes of the basal layer and a number of atypical nuclei which are more numerous in human AK, whereas much more pronounced acanthosis is observed in skin lesion in mice. Thanks to this translational study, we are able to select appropriate experimental conditions for establishing either early or advanced stage AK or an SCC model. Furthermore, we optimized photograph acquisition of AK lesions on mouse skin by using a digital dermatoscope which is also used in clinics and allows reproducible photograph acquisition for further reliable assessment of mouse lesions. Use of this camera is illustrated through a pharmacological study assessing the activity of CARAC®. Conclusion These data demonstrate that this mouse model of UV-B-induced skin lesions is predictive for the identification of novel therapeutic treatments for both early and advanced stages of the disease. PMID:28662116

Estimating site occupancy rates for aquatic plants using spatial sub-sampling designs when detection probabilities are less than one

USGS Publications Warehouse

Nielson, Ryan M.; Gray, Brian R.; McDonald, Lyman L.; Heglund, Patricia J.

2011-01-01

Estimation of site occupancy rates when detection probabilities are <1 is well established in wildlife science. Data from multiple visits to a sample of sites are used to estimate detection probabilities and the proportion of sites occupied by focal species. In this article we describe how site occupancy methods can be applied to estimate occupancy rates of plants and other sessile organisms. We illustrate this approach and the pitfalls of ignoring incomplete detection using spatial data for 2 aquatic vascular plants collected under the Upper Mississippi River's Long Term Resource Monitoring Program (LTRMP). Site occupancy models considered include: a naïve model that ignores incomplete detection, a simple site occupancy model assuming a constant occupancy rate and a constant probability of detection across sites, several models that allow site occupancy rates and probabilities of detection to vary with habitat characteristics, and mixture models that allow for unexplained variation in detection probabilities. We used information theoretic methods to rank competing models and bootstrapping to evaluate the goodness-of-fit of the final models. Results of our analysis confirm that ignoring incomplete detection can result in biased estimates of occupancy rates. Estimates of site occupancy rates for 2 aquatic plant species were 19–36% higher compared to naive estimates that ignored probabilities of detection <1. Simulations indicate that final models have little bias when 50 or more sites are sampled, and little gains in precision could be expected for sample sizes >300. We recommend applying site occupancy methods for monitoring presence of aquatic species.

Taltirelin alleviates fatigue-like behavior in mouse models of cancer-related fatigue.

PubMed

Dougherty, John P; Wolff, Brian S; Cullen, Mary J; Saligan, Leorey N; Gershengorn, Marvin C

2017-10-01

Fatigue affects most cancer patients and has numerous potential causes, including cancer itself and cancer treatment. Cancer-related fatigue (CRF) is not relieved by rest, can decrease quality of life, and has no FDA-approved therapy. Thyrotropin-releasing hormone (TRH) has been proposed as a potential novel treatment for CRF, but its efficacy against CRF remains largely untested. Thus, we tested the TRH analog, taltirelin (TAL), in mouse models of CRF. To model fatigue, we used a mouse model of chemotherapy, a mouse model of radiation therapy, and mice bearing colon 26 carcinoma tumors. We used the treadmill fatigue test to assess fatigue-like behavior after treatment with TAL. Additionally, we used wild-type and TRH receptor knockout mice to determine which TRH receptor was necessary for the actions of TAL. Tumor-bearing mice displayed muscle wasting and all models caused fatigue-like behavior, with mice running a shorter distance in the treadmill fatigue test than controls. TAL reversed fatigue-like behavior in all three models and the mouse TRH 1 receptor was necessary for the effects of TAL. These data suggest that TAL may be useful in alleviating fatigue in all cancer patients and provide further support for evaluating TAL as a potential therapy for CRF in humans. Published by Elsevier Ltd.

The serotonin system in autism spectrum disorder: from biomarker to animal models

PubMed Central

Muller, Christopher L.; Anacker, Allison M.J.; Veenstra-VanderWeele, Jeremy

2015-01-01

Elevated whole blood serotonin, or hyperserotonemia, was the first biomarker identified in autism spectrum disorder (ASD) and is present in more than 25% of affected children. The serotonin system is a logical candidate for involvement in ASD due to its pleiotropic role across multiple brain systems both dynamically and across development. Tantalizing clues connect this peripheral biomarker with changes in brain and behavior in ASD, but the contribution of the serotonin system to ASD pathophysiology remains incompletely understood. Studies of whole blood serotonin levels in ASD and in a large founder population indicate greater heritability than for the disorder itself and suggest an association with recurrence risk. Emerging data from both neuroimaging and postmortem samples also indicate changes in the brain serotonin system in ASD. Genetic linkage and association studies of both whole blood serotonin levels and of ASD risk point to the chromosomal region containing the serotonin transporter (SERT) gene in males but not in females. In ASD families with evidence of linkage to this region, multiple rare SERT amino acid variants lead to a convergent increase in serotonin uptake in cell models. A knock-in mouse model of one of these variants, SERT Gly56Ala, recapitulates the hyperserotonemia biomarker and shows increased brain serotonin clearance, increased serotonin receptor sensitivity, and altered social, communication, and repetitive behaviors. Data from other rodent models also suggest an important role for the serotonin system in social behavior, in cognitive flexibility, and in sensory development. Recent work indicates that reciprocal interactions between serotonin and other systems, such as oxytocin, may be particularly important for social behavior. Collectively, these data point to the serotonin system as a prime candidate for treatment development in a subgroup of children defined by a robust, heritable biomarker. PMID:26577932

MR images of mouse brain using clinical 3T MR scanner and 4CH-Mouse coil

NASA Astrophysics Data System (ADS)

Lim, Soo Mee; Park, Eun Mi; Lyoo, In Kyoon; Lee, Junghyun; Han, Bo Mi; Lee, Jeong Kyong; Lee, Su Bin

2015-07-01

Objectives: Although small-bore high-field magnets are useful for research in small rodent models,this technology, however, has not been easily accessible to most researchers. This current study, thus,tried to evaluate the usability of 4CH-Mouse coil (Philips Healthcare, Best, the Netherlands) forpreclinical investigations in clinical 3T MR scan environment. We evaluated the effects of ischemicpreconditioning (IP) in the mouse stroke model with clinical 3T MR scanner and 4CH-Mouse coil. Materials and Methods: Experiments were performed on male C57BL/6 mice that either received the IP or sham operation (control). Three different MR sequences including diffusion weighted images (DWI), T2-weighted images (T2WI), and fluid attenuated inversion recovery (FLAIR) were performed on the mouse brains following 24, 72 hours of middle cerebral artery occlusion (MCAO) and analyzed for infarct lesions. Results: The images showed that the IP-treated mouse brains had significantly smaller infarct volumes compared to the control group. Of the MR sequences employed, the T2WI showed the highest level of correlations with postmortem infarct volume measurements. Conclusions: The clinical 3T MR scanner turned out to have a solid potential as a practical tool for imaging small animal brains. MR sequences including DWI, T2WI, FLAIR were obtained with acceptable resolution and in a reasonable time constraint in evaluating a mouse stroke model brain.

PACAP38 Differentially Effects Genes and CRMP2 Protein Expression in Ischemic Core and Penumbra Regions of Permanent Middle Cerebral Artery Occlusion Model Mice Brain

PubMed Central

Hori, Motohide; Nakamachi, Tomoya; Shibato, Junko; Rakwal, Randeep; Tsuchida, Masachi; Shioda, Seiji; Numazawa, Satoshi

2014-01-01

Pituitary adenylate-cyclase activating polypeptide (PACAP) has neuroprotective and axonal guidance functions, but the mechanisms behind such actions remain unclear. Previously we examined effects of PACAP (PACAP38, 1 pmol) injection intracerebroventrically in a mouse model of permanent middle cerebral artery occlusion (PMCAO) along with control saline (0.9% NaCl) injection. Transcriptomic and proteomic approaches using ischemic (ipsilateral) brain hemisphere revealed differentially regulated genes and proteins by PACAP38 at 6 and 24 h post-treatment. However, as the ischemic hemisphere consisted of infarct core, penumbra, and non-ischemic regions, specificity of expression and localization of these identified molecular factors remained incomplete. This led us to devise a new experimental strategy wherein, ischemic core and penumbra were carefully sampled and compared to the corresponding contralateral (healthy) core and penumbra regions at 6 and 24 h post PACAP38 or saline injections. Both reverse transcription-polymerase chain reaction (RT-PCR) and Western blotting were used to examine targeted gene expressions and the collapsin response mediator protein 2 (CRMP2) protein profiles, respectively. Clear differences in expression of genes and CRMP2 protein abundance and degradation product/short isoform was observed between ischemic core and penumbra and also compared to the contralateral healthy tissues after PACAP38 or saline treatment. Results indicate the importance of region-specific analyses to further identify, localize and functionally analyse target molecular factors for clarifying the neuroprotective function of PACAP38. PMID:25257527

TWEAK induces liver progenitor cell proliferation

PubMed Central

Jakubowski, Aniela; Ambrose, Christine; Parr, Michael; Lincecum, John M.; Wang, Monica Z.; Zheng, Timothy S.; Browning, Beth; Michaelson, Jennifer S.; Baestcher, Manfred; Wang, Bruce; Bissell, D. Montgomery; Burkly, Linda C.

2005-01-01

Progenitor (“oval”) cell expansion accompanies many forms of liver injury, including alcohol toxicity and submassive parenchymal necrosis as well as experimental injury models featuring blocked hepatocyte replication. Oval cells can potentially become either hepatocytes or biliary epithelial cells and may be critical to liver regeneration, particularly when hepatocyte replication is impaired. The regulation of oval cell proliferation is incompletely understood. Herein we present evidence that a TNF family member called TWEAK (TNF-like weak inducer of apoptosis) stimulates oval cell proliferation in mouse liver through its receptor Fn14. TWEAK has no effect on mature hepatocytes and thus appears to be selective for oval cells. Transgenic mice overexpressing TWEAK in hepatocytes exhibit periportal oval cell hyperplasia. A similar phenotype was obtained in adult wild-type mice, but not Fn14-null mice, by administering TWEAK-expressing adenovirus. Oval cell expansion induced by 3,5-diethoxycarbonyl-1,4-dihydrocollidine (DDC) was significantly reduced in Fn14-null mice as well as in adult wild-type mice with a blocking anti-TWEAK mAb. Importantly, TWEAK stimulated the proliferation of an oval cell culture model. Finally, we show increased Fn14 expression in chronic hepatitis C and other human liver diseases relative to its expression in normal liver, which suggests a role for the TWEAK/Fn14 pathway in human liver injury. We conclude that TWEAK has a selective mitogenic effect for liver oval cells that distinguishes it from other previously described growth factors. PMID:16110324

The chromatin-binding protein Smyd1 restricts adult mammalian heart growth

PubMed Central

Kimball, Todd; Rasmussen, Tara L.; Rosa-Garrido, Manuel; Chen, Haodong; Tran, Tam; Miller, Mickey R.; Gray, Ricardo; Jiang, Shanxi; Ren, Shuxun; Wang, Yibin; Tucker, Haley O.; Vondriska, Thomas M.

2016-01-01

All terminally differentiated organs face two challenges, maintaining their cellular identity and restricting organ size. The molecular mechanisms responsible for these decisions are of critical importance to organismal development, and perturbations in their normal balance can lead to disease. A hallmark of heart failure, a condition affecting millions of people worldwide, is hypertrophic growth of cardiomyocytes. The various forms of heart failure in human and animal models share conserved transcriptome remodeling events that lead to expression of genes normally silenced in the healthy adult heart. However, the chromatin remodeling events that maintain cell and organ size are incompletely understood; insights into these mechanisms could provide new targets for heart failure therapy. Using a quantitative proteomics approach to identify muscle-specific chromatin regulators in a mouse model of hypertrophy and heart failure, we identified upregulation of the histone methyltransferase Smyd1 during disease. Inducible loss-of-function studies in vivo demonstrate that Smyd1 is responsible for restricting growth in the adult heart, with its absence leading to cellular hypertrophy, organ remodeling, and fulminate heart failure. Molecular studies reveal Smyd1 to be a muscle-specific regulator of gene expression and indicate that Smyd1 modulates expression of gene isoforms whose expression is associated with cardiac pathology. Importantly, activation of Smyd1 can prevent pathological cell growth. These findings have basic implications for our understanding of cardiac pathologies and open new avenues to the treatment of cardiac hypertrophy and failure by modulating Smyd1. PMID:27663768

The chromatin-binding protein Smyd1 restricts adult mammalian heart growth.

PubMed

Franklin, Sarah; Kimball, Todd; Rasmussen, Tara L; Rosa-Garrido, Manuel; Chen, Haodong; Tran, Tam; Miller, Mickey R; Gray, Ricardo; Jiang, Shanxi; Ren, Shuxun; Wang, Yibin; Tucker, Haley O; Vondriska, Thomas M

2016-11-01

All terminally differentiated organs face two challenges, maintaining their cellular identity and restricting organ size. The molecular mechanisms responsible for these decisions are of critical importance to organismal development, and perturbations in their normal balance can lead to disease. A hallmark of heart failure, a condition affecting millions of people worldwide, is hypertrophic growth of cardiomyocytes. The various forms of heart failure in human and animal models share conserved transcriptome remodeling events that lead to expression of genes normally silenced in the healthy adult heart. However, the chromatin remodeling events that maintain cell and organ size are incompletely understood; insights into these mechanisms could provide new targets for heart failure therapy. Using a quantitative proteomics approach to identify muscle-specific chromatin regulators in a mouse model of hypertrophy and heart failure, we identified upregulation of the histone methyltransferase Smyd1 during disease. Inducible loss-of-function studies in vivo demonstrate that Smyd1 is responsible for restricting growth in the adult heart, with its absence leading to cellular hypertrophy, organ remodeling, and fulminate heart failure. Molecular studies reveal Smyd1 to be a muscle-specific regulator of gene expression and indicate that Smyd1 modulates expression of gene isoforms whose expression is associated with cardiac pathology. Importantly, activation of Smyd1 can prevent pathological cell growth. These findings have basic implications for our understanding of cardiac pathologies and open new avenues to the treatment of cardiac hypertrophy and failure by modulating Smyd1. Copyright © 2016 the American Physiological Society.

Neurotoxic lupus autoantibodies alter brain function through two distinct mechanisms

PubMed Central

Faust, Thomas W.; Chang, Eric H.; Kowal, Czeslawa; Berlin, RoseAnn; Gazaryan, Irina G.; Bertini, Eva; Zhang, Jie; Sanchez-Guerrero, Jorge; Fragoso-Loyo, Hilda E.; Volpe, Bruce T.; Diamond, Betty; Huerta, Patricio T.

2010-01-01

Damaging interactions between antibodies and brain antigenic targets may be responsible for an expanding range of neurological disorders. In the case of systemic lupus erythematosus (SLE), patients generate autoantibodies (AAbs) that frequently bind dsDNA. Although some symptoms of SLE may arise from direct reactivity to dsDNA, much of the AAb-mediated damage originates from cross-reactivity with other antigens. We have studied lupus AAbs that bind dsDNA and cross-react with the NR2A and NR2B subunits of the NMDA receptor (NMDAR). In adult mouse models, when the blood–brain barrier is compromised, these NMDAR-reactive AAbs access the brain and elicit neuronal death with ensuing cognitive dysfunction and emotional disturbance. The cellular mechanisms that underlie these deleterious effects remain incompletely understood. Here, we show that, at low concentration, the NMDAR-reactive AAbs are positive modulators of receptor function that increase the size of NMDAR-mediated excitatory postsynaptic potentials, whereas at high concentration, the AAbs promote excitotoxicity through enhanced mitochondrial permeability transition. Other synaptic receptors are completely unaffected by the AAbs. NMDAR activation is required for producing both the synaptic and the mitochondrial effects. Our study thus reveals the mechanisms by which NMDAR-reactive AAbs trigger graded cellular alterations, which are likely to be responsible for the transient and permanent neuropsychiatric symptoms observed in patients with SLE. Our study also provides a model in which local AAb concentration determines the exact nature of the cellular response. PMID:20921396

Mutagenicity testing with transgenic mice. Part I: Comparison with the mouse bone marrow micronucleus test

PubMed Central

Wahnschaffe, U; Bitsch, A; Kielhorn, J; Mangelsdorf, I

2005-01-01

As part of a larger literature study on transgenic animals in mutagenicity testing, test results from the transgenic mutagenicity assays (lacI model; commercially available as the Big Blue® mouse, and the lacZ model; commercially available as the Muta™Mouse), were compared with the results on the same substances in the more traditional mouse bone marrow micronucleus test. 39 substances were found which had been tested in the micronucleus assay and in the above transgenic mouse systems. Although, the transgenic animal mutation assay is not directly comparable with the micronucleus test, because different genetic endpoints are examined: chromosome aberration versus gene mutation, the results for the majority of substances were in agreement. Both test systems, the transgenic mouse assay and the mouse bone marrow micronucleus test, have advantages and they complement each other. However, the transgenic animal assay has some distinct advantages over the micronucleus test: it is not restricted to one target organ and detects systemic as well as local mutagenic effects. PMID:15655069

In vivo characterization of a bigenic fluorescent mouse model of Alzheimer's disease with neurodegeneration.

PubMed

Crowe, Sarah E; Ellis-Davies, Graham C R

2013-07-01

The loss of cognitive function in Alzheimer's disease (AD) patients is strongly correlated with the loss of neurons in various regions of the brain. We have created a new fluorescent bigenic mouse model of AD by crossing "H-line" yellow fluorescent protein (YFP) mice with the 5xFAD mouse model, which we call the 5XY mouse model. The 5xFAD mouse has been shown to have significant loss of L5 pyramidal neurons by 12 months of age. These neurons are transgenically labeled with YFP in the 5XY mouse, which enable longitudinal imaging of structural changes. In the 5XY mice, we observed an appearance of axonal dystrophies, with two distinct morphologies in the early stages of the disease progression. Simple swelling dystrophies are transient in nature and are not directly associated with amyloid plaques. Rosette dystrophies are more complex structures that remained stable throughout all imaging sessions, and always surrounded an amyloid plaque. Plaque growth was followed over 4 weeks, and significant growth was seen between weekly imaging sessions. In addition to axonal dystrophy appearance and plaque growth, we were able to follow spine stability in 4-month old 5XY mice, which revealed no significant loss of spines. 5XY mice also showed a striking shrinkage of the neocortex at older ages (12-14 months). The 5XY mouse model may be a valuable tool for studying specific events in the degeneration of the neocortex, and may suggest new avenues for therapeutic intervention. Copyright © 2013 Wiley Periodicals, Inc.

Technique Selectively Represses Immune System

MedlinePlus

... from attacking myelin in a mouse model of multiple sclerosis. Dr David Furness, Wellcome Images. All rights reserved ... devised a way to successfully treat symptoms resembling multiple sclerosis in a mouse model. With further development, the ...

Lipopolysaccharide-induced endotoxemia in corn oil-preloaded mice causes an extended course of lung injury and repair and pulmonary fibrosis: A translational mouse model of acute respiratory distress syndrome.

PubMed

Wu, Chaomin; Evans, Colin E; Dai, Zhiyu; Huang, Xiaojia; Zhang, Xianming; Jin, Hua; Hu, Guochang; Song, Yuanlin; Zhao, You-Yang

2017-01-01

Acute respiratory distress syndrome (ARDS) is characterized by acute hypoxemia respiratory failure, bilateral pulmonary infiltrates, and pulmonary edema of non-cardiac origin. Effective treatments for ARDS patients may arise from experimental studies with translational mouse models of this disease that aim to delineate the mechanisms underlying the disease pathogenesis. Mouse models of ARDS, however, can be limited by their rapid progression from injured to recovery state, which is in contrast to the course of ARDS in humans. Furthermore, current mouse models of ARDS do not recapitulate certain prominent aspects of the pathogenesis of ARDS in humans. In this study, we developed an improved endotoxemic mouse model of ARDS resembling many features of clinical ARDS including extended courses of injury and recovery as well as development of fibrosis following i.p. injection of lipopolysaccharide (LPS) to corn oil-preloaded mice. Compared with mice receiving LPS alone, those receiving corn oil and LPS exhibited extended course of lung injury and repair that occurred over a period of >2 weeks instead of 3-5days. Importantly, LPS challenge of corn oil-preloaded mice resulted in pulmonary fibrosis during the repair phase as often seen in ARDS patients. In summary, this simple novel mouse model of ARDS could represent a valuable experimental tool to elucidate mechanisms that regulate lung injury and repair in ARDS patients.

Endometrial apoptosis and neutrophil infiltration during menstruation exhibits spatial and temporal dynamics that are recapitulated in a mouse model.

PubMed

Armstrong, Gregory M; Maybin, Jacqueline A; Murray, Alison A; Nicol, Moira; Walker, Catherine; Saunders, Philippa T K; Rossi, Adriano G; Critchley, Hilary O D

2017-12-12

Menstruation is characterised by synchronous shedding and restoration of tissue integrity. An in vivo model of menstruation is required to investigate mechanisms responsible for regulation of menstrual physiology and to investigate common pathologies such as heavy menstrual bleeding (HMB). We hypothesised that our mouse model of simulated menstruation would recapitulate the spatial and temporal changes in the inflammatory microenvironment of human menses. Three regulatory events were investigated: cell death (apoptosis), neutrophil influx and cytokine/chemokine expression. Well-characterised endometrial tissues from women were compared with uteri from a mouse model (tissue recovered 0, 4, 8, 24 and 48 h after removal of a progesterone-secreting pellet). Immunohistochemistry for cleaved caspase-3 (CC3) revealed significantly increased staining in human endometrium from late secretory and menstrual phases. In mice, CC3 was significantly increased at 8 and 24 h post-progesterone-withdrawal. Elastase + human neutrophils were maximal during menstruation; Ly6G + mouse neutrophils were maximal at 24 h. Human endometrial and mouse uterine cytokine/chemokine mRNA concentrations were significantly increased during menstrual phase and 24 h post-progesterone-withdrawal respectively. Data from dated human samples revealed time-dependent changes in endometrial apoptosis preceding neutrophil influx and cytokine/chemokine induction during active menstruation. These dynamic changes were recapitulated in the mouse model of menstruation, validating its use in menstrual research.

Bayesian Inference of Natural Rankings in Incomplete Competition Networks

PubMed Central

Park, Juyong; Yook, Soon-Hyung

2014-01-01

Competition between a complex system's constituents and a corresponding reward mechanism based on it have profound influence on the functioning, stability, and evolution of the system. But determining the dominance hierarchy or ranking among the constituent parts from the strongest to the weakest – essential in determining reward and penalty – is frequently an ambiguous task due to the incomplete (partially filled) nature of competition networks. Here we introduce the “Natural Ranking,” an unambiguous ranking method applicable to a round robin tournament, and formulate an analytical model based on the Bayesian formula for inferring the expected mean and error of the natural ranking of nodes from an incomplete network. We investigate its potential and uses in resolving important issues of ranking by applying it to real-world competition networks. PMID:25163528

Past incompleteness of a bouncing multiverse

DOE Office of Scientific and Technical Information (OSTI.GOV)

Vilenkin, Alexander; Zhang, Jun, E-mail: vilenkin@cosmos.phy.tufts.edu, E-mail: jun.zhang@tufts.edu

2014-06-01

According to classical GR, Anti-de Sitter (AdS) bubbles in the multiverse terminate in big crunch singularities. It has been conjectured, however, that the fundamental theory may resolve these singularities and replace them by nonsingular bounces. This may have important implications for the beginning of the multiverse. Geodesics in cosmological spacetimes are known to be past-incomplete, as long as the average expansion rate along the geodesic is positive, but it is not clear that the latter condition is satisfied if the geodesic repeatedly passes through crunching AdS bubbles. We investigate this issue in a simple multiverse model, where the spacetime consistsmore » of a patchwork of FRW regions. The conclusion is that the spacetime is still past-incomplete, even in the presence of AdS bounces.« less

Bayesian Inference of Natural Rankings in Incomplete Competition Networks

NASA Astrophysics Data System (ADS)

Park, Juyong; Yook, Soon-Hyung

2014-08-01

Competition between a complex system's constituents and a corresponding reward mechanism based on it have profound influence on the functioning, stability, and evolution of the system. But determining the dominance hierarchy or ranking among the constituent parts from the strongest to the weakest - essential in determining reward and penalty - is frequently an ambiguous task due to the incomplete (partially filled) nature of competition networks. Here we introduce the ``Natural Ranking,'' an unambiguous ranking method applicable to a round robin tournament, and formulate an analytical model based on the Bayesian formula for inferring the expected mean and error of the natural ranking of nodes from an incomplete network. We investigate its potential and uses in resolving important issues of ranking by applying it to real-world competition networks.

Neoplastic cell transformation by high-LET radiation - Molecular mechanisms

NASA Technical Reports Server (NTRS)

Yang, Tracy Chui-Hsu; Craise, Laurie M.; Tobias, Cornelius A.; Mei, Man-Tong

1989-01-01

Quantitative data were collected on dose-response curves of cultured mouse-embryo cells (C3H10T1/2) irradiated with heavy ions of various charges and energies. Results suggests that two breaks formed on DNA within 80 A may cause cell transformation and that two DNA breaks formed within 20 A may be lethal. From results of experiments with restriction enzymes which produce DNA damages at specific sites, it was found that DNA double strand breaks are important primary lesions for radiogenic cell transformation and that blunt-ended double-strand breaks can form lethal as well as transformational damages due to misrepair or incomplete repair in the cell. The RBE-LET relationship for high-LET radiation is similar to that for HGPRT locus mutation, chromosomal deletion, and cell transformation, indicating that common lesions may be involved in these radiation effects.

A novel ALS-associated variant in UBQLN4 regulates motor axon morphogenesis

PubMed Central

Edens, Brittany M; Yan, Jianhua; Miller, Nimrod; Deng, Han-Xiang; Siddique, Teepu; Ma, Yongchao C

2017-01-01

The etiological underpinnings of amyotrophic lateral sclerosis (ALS) are complex and incompletely understood, although contributions to pathogenesis by regulators of proteolytic pathways have become increasingly apparent. Here, we present a novel variant in UBQLN4 that is associated with ALS and show that its expression compromises motor axon morphogenesis in mouse motor neurons and in zebrafish. We further demonstrate that the ALS-associated UBQLN4 variant impairs proteasomal function, and identify the Wnt signaling pathway effector beta-catenin as a UBQLN4 substrate. Inhibition of beta-catenin function rescues the UBQLN4 variant-induced motor axon phenotypes. These findings provide a strong link between the regulation of axonal morphogenesis and a new ALS-associated gene variant mediated by protein degradation pathways. DOI: http://dx.doi.org/10.7554/eLife.25453.001 PMID:28463112

The STR/ort mouse model of spontaneous osteoarthritis - an update.

PubMed

Staines, K A; Poulet, B; Wentworth, D N; Pitsillides, A A

2017-06-01

Osteoarthritis is a degenerative joint disease and a world-wide healthcare burden. Characterized by cartilage degradation, subchondral bone thickening and osteophyte formation, osteoarthritis inflicts much pain and suffering, for which there are currently no disease-modifying treatments available. Mouse models of osteoarthritis are proving critical in advancing our understanding of the underpinning molecular mechanisms. The STR/ort mouse is a well-recognized model which develops a natural form of osteoarthritis very similar to the human disease. In this Review we discuss the use of the STR/ort mouse in understanding this multifactorial disease with an emphasis on recent advances in its genetics and its bone, endochondral and immune phenotypes. Copyright © 2016 The Authors. Published by Elsevier Ltd.. All rights reserved.

Mouse brain magnetic resonance microscopy: Applications in Alzheimer disease.

PubMed

Lin, Lan; Fu, Zhenrong; Xu, Xiaoting; Wu, Shuicai

2015-05-01

Over the past two decades, various Alzheimer's disease (AD) trangenetic mice models harboring genes with mutation known to cause familial AD have been created. Today, high-resolution magnetic resonance microscopy (MRM) technology is being widely used in the study of AD mouse models. It has greatly facilitated and advanced our knowledge of AD. In this review, most of the attention is paid to fundamental of MRM, the construction of standard mouse MRM brain template and atlas, the detection of amyloid plaques, following up on brain atrophy and the future applications of MRM in transgenic AD mice. It is believed that future testing of potential drugs in mouse models with MRM will greatly improve the predictability of drug effect in preclinical trials. © 2015 Wiley Periodicals, Inc.

Better Utilization of Mouse Models of Neurodegenerative Diseases in Preclinical Studies: From the Bench to the Clinic.

PubMed

Janus, Christopher; Hernandez, Carolina; deLelys, Victoria; Roder, Hanno; Welzl, Hans

2016-01-01

The major symptom of Alzheimer's disease is dementia progressing with age. Its clinical diagnosis is preceded by a long prodromal period of brain pathology that encompasses both formation of extracellular amyloid and intraneuronal tau deposits in the brain and widespread neuronal death. At present, familial cases of dementia provide the most promising foundation for modeling neurodegenerative tauopathies, a group of heterogeneous disorders characterized by prominent intracellular accumulation of hyperphosphorylated tau protein. In this chapter, we describe major behavioral hallmarks of tauopathies, briefly outline the genetics underlying familial cases, and discuss the arising implications for modeling the disease in transgenic mouse systems. The selection of tests performed to evaluate the phenotype of a model should be guided by the key behavioral hallmarks that characterize human disorder and their homology to mouse cognitive systems. We attempt to provide general guidelines and establish criteria for modeling dementia in a mouse; however, interpretations of obtained results should avoid a reductionist "one gene, one disease" explanation of model characteristics. Rather, the focus should be directed to the question of how the mouse genome can cope with the over-expression of the protein coded by transgene(s). While each model is valuable within its own constraints and the experiments performed are guided by specific hypotheses, we seek to expand upon their methodology by offering guidance spanning from issues of mouse husbandry to choices of behavioral tests and routes of drug administration that might increase the external validity of studies and consequently optimize the translational aspect of preclinical research.

Rodent models of congenital and hereditary cataract in man.

PubMed

Tripathi, B J; Tripathi, R C; Borisuth, N S; Dhaliwal, R; Dhaliwal, D

1991-01-01

Because the organogenesis and physiology of the lens are essentially similar in various mammals, an understanding of the etiology and pathogenesis of the formation of cataract in an animal model will enhance our knowledge of cataractogenesis in man. In this review, we summarize the background, etiology, and pathogenesis of cataracts that occur in rodents. The main advantages of using rodent mutants include the well-researched genetics of the animals and the comparative ease of breeding of large litters. Numerous rodent models of congenital and hereditary cataracts have been studied extensively. In mice, the models include the Cts strain, Fraser mouse, lens opacity gene (Lop) strain, Lop-2 and Lop-3 strains, Philly mouse, Nakano mouse, Nop strain, Deer mouse, Emory mouse, Swiss Webster strain, Balb/c-nct/nct mouse, and SAM-R/3 strain. The rat models include BUdR, ICR, Sprague-Dawley, and Wistar rats, the spontaneously hypertensive rat (SHR), the John Rapp inbred strain of Dahl salt-sensitive rat, as well as WBN/Kob, Royal College of Surgeons (RCS), and Brown-Norway rats. Other proposed models for the study of hereditary cataract include the degu and the guinea pig. Because of the ease of making clinical observations in vivo and the subsequent availability of the intact lens for laboratory analyses at different stages of cataract formation, these animals provide excellent models for clinicopathologic correlations, for monitoring of the natural history of the aging process and of metabolic defects, as well as for investigations on the effect of cataract-modulating agents and drugs, including the prospect of gene therapy.

The neuroregenerative capacity of olfactory stem cells is not limitless: implications for aging.

PubMed

Child, Kevin M; Herrick, Daniel B; Schwob, James E; Holbrook, Eric H; Jang, Woochan

2018-06-22

The olfactory epithelium (OE) of vertebrates is a highly regenerative neuroepithelium, maintained under normal condition by a population of stem and progenitor cells - globose basal cells (GBCs) that also contribute to epithelial reconstitution after injury. However, aging of the OE often leads to neurogenic exhaustion - the disappearance of both GBCs and olfactory sensory neurons (OSNs). Aneuronal tissue may remain as olfactory, with an uninterrupted sheet of apically arrayed microvillar-capped sustentacular cell, or may undergo respiratory metaplasia. We have generated a transgenic mouse model for neurogenic exhaustion using OMP-driven Tet-off regulation of the A subunit of Diphtheria toxin such that the death of mature OSNs is accelerated. As early as 2 months of age the epithelium of transgenic mice, regardless of sex, recapitulates what is seen in the aged OE of humans and rodents. Areas of the epithelium completely lack neurons and GBCs, while the horizontal basal cells, a reserve stem cell population, show no evidence of activation. Surprisingly, other areas that were olfactory undergo respiratory metaplasia. The impact of accelerated neuronal death and reduced innervation on the olfactory bulb (OB) is also examined. Constant neuronal turnover leaves glomeruli shrunken and impacts the dopaminergic interneurons in the periglomerular layer. Moreover, the acceleration of OSN death can be reversed in those areas where some GBCs persist. However, the projection onto the OB recovers incompletely and the reinnervated glomeruli are markedly altered. Thus, the capacity for OE regeneration is tempered when GBCs disappear. SIGNIFICANCE STATEMENT A large percentage of humans lose or suffer a significant decline in olfactory function as they age. Consequently, quality of life suffers, and safety and nutritional status are put at risk. With age, the OE apparently becomes incapable of fully maintaining the neuronal population of the epithelium despite its well-known capacity for recovering from most forms of injury when younger which may contribute to age-related olfactory loss. Efforts to identify the mechanism by which olfactory neurogenesis becomes exhausted with age require a powerful model for accelerating age-related tissue pathology. The current OMP-tTA ; TetO-DTA transgenic mouse model, in which olfactory neurons die when they reach maturity and accelerated death can be aborted to assess the capacity for structural recovery, satisfies that need. Copyright © 2018 the authors.

SCIENTIFIC UNCERTAINTIES IN ATMOSPHERIC MERCURY MODELS II: SENSITIVITY ANALYSIS IN THE CONUS DOMAIN

EPA Science Inventory

In this study, we present the response of model results to different scientific treatments in an effort to quantify the uncertainties caused by the incomplete understanding of mercury science and by model assumptions in atmospheric mercury models. Two sets of sensitivity simulati...

Mouse Genome Informatics (MGI) Is the International Resource for Information on the Laboratory Mouse.

PubMed

Law, MeiYee; Shaw, David R

2018-01-01

Mouse Genome Informatics (MGI, http://www.informatics.jax.org/ ) web resources provide free access to meticulously curated information about the laboratory mouse. MGI's primary goal is to help researchers investigate the genetic foundations of human diseases by translating information from mouse phenotypes and disease models studies to human systems. MGI provides comprehensive phenotypes for over 50,000 mutant alleles in mice and provides experimental model descriptions for over 1500 human diseases. Curated data from scientific publications are integrated with those from high-throughput phenotyping and gene expression centers. Data are standardized using defined, hierarchical vocabularies such as the Mammalian Phenotype (MP) Ontology, Mouse Developmental Anatomy and the Gene Ontologies (GO). This chapter introduces you to Gene and Allele Detail pages and provides step-by-step instructions for simple searches and those that take advantage of the breadth of MGI data integration.

Differential biological effects of dehydroepiandrosterone (DHEA) between mouse (B16F10) and human melanoma (BLM) cell lines.

PubMed

Joshi, Kumud; Hassan, Sherif S; Ramaraj, Pandurangan

2017-01-01

Dehydroepiandrosterone (DHEA) is a weak androgen and had been shown to have anti-cancer, anti-adipogenic and anti-inflammatory effects on mouse and other rodent models, but not on humans, suggesting a systemic level difference between mouse and human. Our previous study on DHEA biological functions involving a variety of cell lines, suggested that the functional differences between mouse and human existed even at the cellular level. Hence, using mouse and human melanoma cell models, in-vitro effects of DHEA on cell growth, mechanism of cell death and mechanism of DHEA action were studied. Results indicated a differential biological effects of DHEA between mouse and human melanoma cell lines. These in-vitro studies also suggested that the differential biological effects observed between these two cell lines could be due to the difference in the way DHEA was processed or metabolized inside the cell.

Current State of Animal (Mouse) Modeling in Melanoma Research.

PubMed

Kuzu, Omer F; Nguyen, Felix D; Noory, Mohammad A; Sharma, Arati

2015-01-01

Despite the considerable progress in understanding the biology of human cancer and technological advancement in drug discovery, treatment failure remains an inevitable outcome for most cancer patients with advanced diseases, including melanoma. Despite FDA-approved BRAF-targeted therapies for advanced stage melanoma showed a great deal of promise, development of rapid resistance limits the success. Hence, the overall success rate of melanoma therapy still remains to be one of the worst compared to other malignancies. Advancement of next-generation sequencing technology allowed better identification of alterations that trigger melanoma development. As development of successful therapies strongly depends on clinically relevant preclinical models, together with the new findings, more advanced melanoma models have been generated. In this article, besides traditional mouse models of melanoma, we will discuss recent ones, such as patient-derived tumor xenografts, topically inducible BRAF mouse model and RCAS/TVA-based model, and their advantages as well as limitations. Although mouse models of melanoma are often criticized as poor predictors of whether an experimental drug would be an effective treatment, development of new and more relevant models could circumvent this problem in the near future.

Identification of novel mRNAs and lncRNAs associated with mouse experimental colitis and human inflammatory bowel disease.

PubMed

Rankin, Carl Robert; Theodorou, Evangelos; Law, Ivy Ka Man; Rowe, Lorraine; Kokkotou, Efi; Pekow, Joel; Wang, Jiafang; Martin, Martin G; Pothoulakis, Charalabos; Padua, David Miguel

2018-06-28

Inflammatory bowel disease (IBD) is a complex disorder that is associated with significant morbidity. While many recent advances have been made with new diagnostic and therapeutic tools, a deeper understanding of its basic pathophysiology is needed to continue this trend towards improving treatments. By utilizing an unbiased, high-throughput transcriptomic analysis of two well-established mouse models of colitis, we set out to uncover novel coding and non-coding RNAs that are differentially expressed in the setting of colonic inflammation. RNA-seq analysis was performed using colonic tissue from two mouse models of colitis, a dextran sodium sulfate induced model and a genetic-induced model in mice lacking IL-10. We identified 81 coding RNAs that were commonly altered in both experimental models. Of these coding RNAs, 12 of the human orthologs were differentially expressed in a transcriptomic analysis of IBD patients. Interestingly, 5 of the 12 of human differentially expressed genes have not been previously identified as IBD-associated genes, including ubiquitin D. Our analysis also identified 15 non-coding RNAs that were differentially expressed in either mouse model. Surprisingly, only three non-coding RNAs were commonly dysregulated in both of these models. The discovery of these new coding and non-coding RNAs expands our transcriptional knowledge of mouse models of IBD and offers additional targets to deepen our understanding of the pathophysiology of IBD.

A Dynamic Simulation of Musculoskeletal Function in the Mouse Hindlimb During Trotting Locomotion

PubMed Central

Charles, James P.; Cappellari, Ornella; Hutchinson, John R.

2018-01-01

Mice are often used as animal models of various human neuromuscular diseases, and analysis of these models often requires detailed gait analysis. However, little is known of the dynamics of the mouse musculoskeletal system during locomotion. In this study, we used computer optimization procedures to create a simulation of trotting in a mouse, using a previously developed mouse hindlimb musculoskeletal model in conjunction with new experimental data, allowing muscle forces, activation patterns, and levels of mechanical work to be estimated. Analyzing musculotendon unit (MTU) mechanical work throughout the stride allowed a deeper understanding of their respective functions, with the rectus femoris MTU dominating the generation of positive and negative mechanical work during the swing and stance phases. This analysis also tested previous functional inferences of the mouse hindlimb made from anatomical data alone, such as the existence of a proximo-distal gradient of muscle function, thought to reflect adaptations for energy-efficient locomotion. The results do not strongly support the presence of this gradient within the mouse musculoskeletal system, particularly given relatively high negative net work output from the ankle plantarflexor MTUs, although more detailed simulations could test this further. This modeling analysis lays a foundation for future studies of the control of vertebrate movement through the development of neuromechanical simulations. PMID:29868576

Additive interactions between 1-methyl-1,2,3,4-tetrahydroisoquinoline and clobazam in the mouse maximal electroshock-induced tonic seizure model--an isobolographic analysis for parallel dose-response relationship curves.

PubMed

Andres-Mach, Marta; Haratym-Maj, Agnieszka; Zagaja, Mirosław; Luszczki, Jarogniew J

2014-01-01

The aim of this study was to characterize the anticonvulsant effect of 1-methyl-1,2,3,4-tetrahydroisoquinoline (1-MeTHIQ) in combination with clobazam (CLB) in the mouse maximal electroshock-induced seizure (MES) model. The anticonvulsant interaction profile between 1-MeTHIQ and CLB in the mouse MES model was determined using an isobolographic analysis for parallel dose-response relationship curves. Electroconvulsions were produced in albino Swiss mice by a current (sine wave, 25 mA, 500 V, 50 Hz, 0.2-second stimulus duration) delivered via auricular electrodes by a Hugo Sachs generator. There was an additive effect of the combination of 1-MeTHIQ with CLB (at the fixed ratios of 1:3, 1:1 and 3:1) in the mouse MES-induced tonic seizure model. The additive interaction of the combination of 1-MeTHIQ with CLB (at fixed-ratios of 1:3, 1:1 and 3:1) in the mouse MES model seems to be pharmacodynamic in nature and worth of considering in further clinical practice. © 2014 S. Karger AG, Basel.

Improvements and Limitations of Humanized Mouse Models for HIV Research: NIH/NIAID “Meet the Experts” 2015 Workshop Summary

PubMed Central

Akkina, Ramesh; Allam, Atef; Balazs, Alejandro B.; Blankson, Joel N.; Burnett, John C.; Casares, Sofia; Garcia, J. Victor; Hasenkrug, Kim J.; Kitchen, Scott G.; Klein, Florian; Kumar, Priti; Luster, Andrew D.; Poluektova, Larisa Y.; Rao, Mangala; Shultz, Leonard D.; Zack, Jerome A.

2016-01-01

Abstract The number of humanized mouse models for the human immunodeficiency virus (HIV)/acquired immunodeficiency syndrome (AIDS) and other infectious diseases has expanded rapidly over the past 8 years. Highly immunodeficient mouse strains, such as NOD/SCID/gamma chainnull (NSG, NOG), support better human hematopoietic cell engraftment. Another improvement is the derivation of highly immunodeficient mice, transgenic with human leukocyte antigens (HLAs) and cytokines that supported development of HLA-restricted human T cells and heightened human myeloid cell engraftment. Humanized mice are also used to study the HIV reservoir using new imaging techniques. Despite these advances, there are still limitations in HIV immune responses and deficits in lymphoid structures in these models in addition to xenogeneic graft-versus-host responses. To understand and disseminate the improvements and limitations of humanized mouse models to the scientific community, the NIH sponsored and convened a meeting on April 15, 2015 to discuss the state of knowledge concerning these questions and best practices for selecting a humanized mouse model for a particular scientific investigation. This report summarizes the findings of the NIH meeting. PMID:26670361

Behavioral assays with mouse models of Alzheimer’s disease: practical considerations and guidelines

PubMed Central

Puzzo, Daniela; Lee, Linda; Palmeri, Agostino; Calabrese, Giorgio; Arancio, Ottavio

2014-01-01

In Alzheimer’s disease (AD) basic research and drug discovery, mouse models are essential resources for uncovering biological mechanisms, validating molecular targets and screening potential compounds. Both transgenic and non-genetically modified mouse models enable access to different types of AD-like pathology in vivo. Although there is a wealth of genetic and biochemical studies on proposed AD pathogenic pathways, as a disease that centrally features cognitive failure, the ultimate readout for any interventions should be measures of learning and memory. This is particularly important given the lack of knowledge on disease etiology – assessment by cognitive assays offers the advantage of targeting relevant memory systems without requiring assumptions about pathogenesis. A multitude of behavioral assays are available for assessing cognitive functioning in mouse models, including ones specific for hippocampal-dependent learning and memory. Here we review the basics of available transgenic and non-transgenic AD mouse models and detail three well-established behavioral tasks commonly used for testing hippocampal-dependent cognition in mice – contextual fear conditioning, radial arm water maze and Morris water maze. In particular, we discuss the practical considerations, requirements and caveats of these behavioral testing paradigms. PMID:24462904

Icotinib inhibits EGFR signaling and alleviates psoriasis-like symptoms in animal models.

PubMed

Tan, Fenlai; Yang, Guiqun; Wang, Yanping; Chen, Haibo; Yu, Bo; Li, He; Guo, Jing; Huang, Xiaoling; Deng, Yifang; Yu, Pengxia; Ding, Lieming

2018-02-01

To investigate the effects of icotinib hydrochloride and a derivative cream on epidermal growth factor receptor (EGFR) signaling and within animal psoriasis models, respectively. The effect of icotinib on EGFR signaling was examined in HaCaT cells, while its effect on angiogenesis was tested in chick embryo chorioallantoic membranes (CAM). The effectiveness of icotinib in treating psoriasis was tested in three psoriasis models, including diethylstilbestrol-treated mouse vaginal epithelial cells, mouse tail granular cell layer formation, and propranolol-induced psoriasis-like features in guinea pig ear skin. Icotinib treatment blocked EGFR signaling and reduced HaCaT cell viability as well as suppressed CAM angiogenesis. Topical application of icotinib ameliorated psoriasis-like histological characteristics in mouse and guinea pig psoriasis models. Icotinib also significantly inhibited mouse vaginal epithelium mitosis, promoted mouse tail squamous epidermal granular layer formation, and reduced the thickness of the horny layer in propranolol treated auricular dorsal surface of guinea pig. We conclude that icotinib can effectively inhibit psoriasis in animal models. Future clinical studies should be conducted to explore the therapeutic effects of icotinb in humans. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

Pathogenicity of swine influenza viruses possessing an avian or swine-origin PB2 polymerase gene evaluated in mouse and pig models.

PubMed

Ma, Wenjun; Lager, Kelly M; Li, Xi; Janke, Bruce H; Mosier, Derek A; Painter, Laura E; Ulery, Eva S; Ma, Jingqun; Lekcharoensuk, Porntippa; Webby, Richard J; Richt, Jürgen A

2011-02-05

PB2 627K is a determinant of influenza host range and contributes to the pathogenicity of human-, avian-, and mouse-adapted influenza viruses in the mouse model. Here we used mouse and pig models to analyze the contribution of a swine-origin and avian-origin PB2 carrying either 627K or 627E in the background of the classical swine H1N1 (A/Swine/Iowa/15/30; 1930) virus. The results showed PB2 627K is crucial for virulence in the mouse model, independent of whether PB2 is derived from an avian or swine influenza virus (SIV). In the pig model, PB2 627E decreases pathogenicity of the classical 1930 SIV when it contains the swine-origin PB2, but not when it possesses the avian-origin PB2. Our study suggests the pathogenicity of SIVs with different PB2 genes and mutation of codon 627 in mice does not correlate with the pathogenicity of the same SIVs in the natural host, the pig. Copyright © 2010 Elsevier Inc. All rights reserved.

An Immunocompetent Mouse Model of Zika Virus Infection.

PubMed

Gorman, Matthew J; Caine, Elizabeth A; Zaitsev, Konstantin; Begley, Matthew C; Weger-Lucarelli, James; Uccellini, Melissa B; Tripathi, Shashank; Morrison, Juliet; Yount, Boyd L; Dinnon, Kenneth H; Rückert, Claudia; Young, Michael C; Zhu, Zhe; Robertson, Shelly J; McNally, Kristin L; Ye, Jing; Cao, Bin; Mysorekar, Indira U; Ebel, Gregory D; Baric, Ralph S; Best, Sonja M; Artyomov, Maxim N; Garcia-Sastre, Adolfo; Diamond, Michael S

2018-05-09

Progress toward understanding Zika virus (ZIKV) pathogenesis is hindered by lack of immunocompetent small animal models, in part because ZIKV fails to effectively antagonize Stat2-dependent interferon (IFN) responses in mice. To address this limitation, we first passaged an African ZIKV strain (ZIKV-Dak-41525) through Rag1 -/- mice to obtain a mouse-adapted virus (ZIKV-Dak-MA) that was more virulent than ZIKV-Dak-41525 in mice treated with an anti-Ifnar1 antibody. A G18R substitution in NS4B was the genetic basis for the increased replication, and resulted in decreased IFN-β production, diminished IFN-stimulated gene expression, and the greater brain infection observed with ZIKV-Dak-MA. To generate a fully immunocompetent mouse model of ZIKV infection, human STAT2 was introduced into the mouse Stat2 locus (hSTAT2 KI). Subcutaneous inoculation of pregnant hSTAT2 KI mice with ZIKV-Dak-MA resulted in spread to the placenta and fetal brain. An immunocompetent mouse model of ZIKV infection may prove valuable for evaluating countermeasures to limit disease. Copyright © 2018 Elsevier Inc. All rights reserved.

Histologic scoring of gastritis and gastric cancer in mouse models.

PubMed

Rogers, Arlin B

2012-01-01

Histopathology is a defining endpoint in mouse models of experimental gastritis and gastric adenocarcinoma. Presented here is an overview of the histology of gastritis and gastric cancer in mice experimentally infected with Helicobacter pylori or H. felis. A modular histopathologic scoring scheme is provided that incorporates relevant disease-associated changes. Whereas the guide uses Helicobacter infection as the prototype challenge, features may be applied to chemical and genetically engineered mouse models of stomach cancer as well. Specific criteria included in the combined gastric histologic activity index (HAI) include inflammation, epithelial defects, oxyntic atrophy, hyperplasia, pseudopyloric metaplasia, and dysplasia or neoplasia. Representative photomicrographs accompany descriptions for each lesion grade. Differentiation of genuine tumor invasion from pseudoinvasion is highlighted. A brief comparison of normal rodent versus human stomach anatomy and physiology is accompanied by an introduction to mouse-specific lesions including mucous metaplasia and eosinophilic droplets (hyalinosis). In conjunction with qualified pathology support, this guide is intended to assist research scientists, postdoctoral fellows, graduate students, and medical professionals from affiliated disciplines in the interpretation and histologic grading of chronic gastritis and gastric carcinoma in mouse models.

Sequential estimation and satellite data assimilation in meteorology and oceanography

NASA Technical Reports Server (NTRS)

Ghil, M.

1986-01-01

The role of dynamics in estimating the state of the atmosphere and ocean from incomplete and noisy data is discussed and the classical applications of four-dimensional data assimilation to large-scale atmospheric dynamics are presented. It is concluded that sequential updating of a forecast model with continuously incoming conventional and remote-sensing data is the most natural way of extracting the maximum amount of information from the imperfectly known dynamics, on the one hand, and the inaccurate and incomplete observations, on the other.

Astonishing advances in mouse genetic tools for biomedical research.

PubMed

Kaczmarczyk, Lech; Jackson, Walker S

2015-01-01

The humble house mouse has long been a workhorse model system in biomedical research. The technology for introducing site-specific genome modifications led to Nobel Prizes for its pioneers and opened a new era of mouse genetics. However, this technology was very time-consuming and technically demanding. As a result, many investigators continued to employ easier genome manipulation methods, though resulting models can suffer from overlooked or underestimated consequences. Another breakthrough, invaluable for the molecular dissection of disease mechanisms, was the invention of high-throughput methods to measure the expression of a plethora of genes in parallel. However, the use of samples containing material from multiple cell types could obfuscate data, and thus interpretations. In this review we highlight some important issues in experimental approaches using mouse models for biomedical research. We then discuss recent technological advances in mouse genetics that are revolutionising human disease research. Mouse genomes are now easily manipulated at precise locations thanks to guided endonucleases, such as transcription activator-like effector nucleases (TALENs) or the CRISPR/Cas9 system, both also having the potential to turn the dream of human gene therapy into reality. Newly developed methods of cell type-specific isolation of transcriptomes from crude tissue homogenates, followed by detection with next generation sequencing (NGS), are vastly improving gene regulation studies. Taken together, these amazing tools simplify the creation of much more accurate mouse models of human disease, and enable the extraction of hitherto unobtainable data.

Mutational landscape of a chemically-induced mouse model of liver cancer.

PubMed

Connor, Frances; Rayner, Tim F; Aitken, Sarah J; Feig, Christine; Lukk, Margus; Santoyo-Lopez, Javier; Odom, Duncan T

2018-06-26

Carcinogen-induced mouse models of liver cancer are used extensively to study pathogenesis of the disease and have a critical role in validating candidate therapeutics. These models can recapitulate molecular and histological features of human disease. However, it is not known if the genomic alterations driving these mouse tumour genomes are comparable to those found in human tumours. Here, we provide a detailed genomic characterisation of tumours from a commonly used mouse model of hepatocellular carcinoma (HCC). We analysed whole exome sequences of liver tumours arising in mice exposed to diethylnitrosamine (DEN). DEN-initiated tumours had a high, uniform number of somatic single nucleotide variants (SNVs), with few insertions, deletions or copy number alterations, consistent with the known genotoxic action of DEN. Exposure of hepatocytes to DEN left a reproducible mutational imprint in resulting tumour exomes which we could computationally reconstruct using six known COSMIC mutational signatures. The tumours carried a high diversity of low-incidence, non-synonymous point mutations in many oncogenes and tumour suppressors, reflecting the stochastic introduction of SNVs into the hepatocyte genome by the carcinogen. We identified four recurrently mutated genes that were putative oncogenic drivers of HCC in this model. Every neoplasm carried activating hotspot mutations either in codon 61 of Hras, in codon 584 of Braf or in codon 254 of Egfr. Truncating mutations of Apc occurred in 21% of neoplasms, which were exclusively carcinomas supporting a role for deregulation of Wnt/β-catenin signalling in cancer progression. Our study provides detailed insight into the mutational landscape of tumours arising in a commonly-used carcinogen model of HCC, facilitating the future use of this model to understand the human disease. Mouse models are widely used to study the biology of cancer and to test potential therapies. Here, we have described the mutational landscape of tumours arising in a carcinogen-induced mouse model of liver cancer. Since cancer is a disease caused by genomic alterations, information about the patterns and types of mutations in the tumours in this mouse model should facilitate its use to study human liver cancer. Copyright © 2018 European Association for the Study of the Liver. Published by Elsevier B.V. All rights reserved.

LungMAP: The Molecular Atlas of Lung Development Program.

PubMed

Ardini-Poleske, Maryanne E; Clark, Robert F; Ansong, Charles; Carson, James P; Corley, Richard A; Deutsch, Gail H; Hagood, James S; Kaminski, Naftali; Mariani, Thomas J; Potter, Steven S; Pryhuber, Gloria S; Warburton, David; Whitsett, Jeffrey A; Palmer, Scott M; Ambalavanan, Namasivayam

2017-11-01

The National Heart, Lung, and Blood Institute is funding an effort to create a molecular atlas of the developing lung (LungMAP) to serve as a research resource and public education tool. The lung is a complex organ with lengthy development time driven by interactive gene networks and dynamic cross talk among multiple cell types to control and coordinate lineage specification, cell proliferation, differentiation, migration, morphogenesis, and injury repair. A better understanding of the processes that regulate lung development, particularly alveologenesis, will have a significant impact on survival rates for premature infants born with incomplete lung development and will facilitate lung injury repair and regeneration in adults. A consortium of four research centers, a data coordinating center, and a human tissue repository provides high-quality molecular data of developing human and mouse lungs. LungMAP includes mouse and human data for cross correlation of developmental processes across species. LungMAP is generating foundational data and analysis, creating a web portal for presentation of results and public sharing of data sets, establishing a repository of young human lung tissues obtained through organ donor organizations, and developing a comprehensive lung ontology that incorporates the latest findings of the consortium. The LungMAP website (www.lungmap.net) currently contains more than 6,000 high-resolution lung images and transcriptomic, proteomic, and lipidomic human and mouse data and provides scientific information to stimulate interest in research careers for young audiences. This paper presents a brief description of research conducted by the consortium, database, and portal development and upcoming features that will enhance the LungMAP experience for a community of users. Copyright © 2017 the American Physiological Society.

Birthdating of myenteric neuron subtypes in the small intestine of the mouse.

PubMed

Bergner, Annette J; Stamp, Lincon A; Gonsalvez, David G; Allison, Margaret B; Olson, David P; Myers, Martin G; Anderson, Colin R; Young, Heather M

2014-02-15

There are many different types of enteric neurons. Previous studies have identified the time at which some enteric neuron subtypes are born (exit the cell cycle) in the mouse, but the birthdates of some major enteric neuron subtypes are still incompletely characterized or unknown. We combined 5-ethynynl-2'-deoxyuridine (EdU) labeling with antibody markers that identify myenteric neuron subtypes to determine when neuron subtypes are born in the mouse small intestine. We found that different neurochemical classes of enteric neuron differed in their birthdates; serotonin neurons were born first with peak cell cycle exit at E11.5, followed by neurofilament-M neurons, calcitonin gene-related peptide neurons (peak cell cycle exit for both at embryonic day [E]12.5-E13.5), tyrosine hydroxylase neurons (E15.5), nitric oxide synthase 1 (NOS1) neurons (E15.5), and calretinin neurons (postnatal day [P]0). The vast majority of myenteric neurons had exited the cell cycle by P10. We did not observe any EdU+/NOS1+ myenteric neurons in the small intestine of adult mice following EdU injection at E10.5 or E11.5, which was unexpected, as previous studies have shown that NOS1 neurons are present in E11.5 mice. Studies using the proliferation marker Ki67 revealed that very few NOS1 neurons in the E11.5 and E12.5 gut were proliferating. However, Cre-lox-based genetic fate-mapping revealed a small subpopulation of myenteric neurons that appears to express NOS1 only transiently. Together, our results confirm a relationship between enteric neuron subtype and birthdate, and suggest that some enteric neurons exhibit neurochemical phenotypes during development that are different from their mature phenotype. Copyright © 2013 Wiley Periodicals, Inc.

A novel multisensor traffic state assessment system based on incomplete data.

PubMed

Zeng, Yiliang; Lan, Jinhui; Ran, Bin; Jiang, Yaoliang

2014-01-01

A novel multisensor system with incomplete data is presented for traffic state assessment. The system comprises probe vehicle detection sensors, fixed detection sensors, and traffic state assessment algorithm. First of all, the validity checking of the traffic flow data is taken as preprocessing of this method. And then a new method based on the history data information is proposed to fuse and recover the incomplete data. According to the characteristics of space complementary of data based on the probe vehicle detector and fixed detector, a fusion model of space matching is presented to estimate the mean travel speed of the road. Finally, the traffic flow data include flow, speed and, occupancy rate, which are detected between Beijing Deshengmen bridge and Drum Tower bridge, are fused to assess the traffic state of the road by using the fusion decision model of rough sets and cloud. The accuracy of experiment result can reach more than 98%, and the result is in accordance with the actual road traffic state. This system is effective to assess traffic state, and it is suitable for the urban intelligent transportation system.

Statistical aspects of point count sampling

USGS Publications Warehouse

Barker, R.J.; Sauer, J.R.; Ralph, C.J.; Sauer, J.R.; Droege, S.

1995-01-01

The dominant feature of point counts is that they do not census birds, but instead provide incomplete counts of individuals present within a survey plot. Considering a simple model for point count sampling, we demon-strate that use of these incomplete counts can bias estimators and testing procedures, leading to inappropriate conclusions. A large portion of the variability in point counts is caused by the incomplete counting, and this within-count variation can be confounded with ecologically meaningful varia-tion. We recommend caution in the analysis of estimates obtained from point counts. Using; our model, we also consider optimal allocation of sampling effort. The critical step in the optimization process is in determining the goals of the study and methods that will be used to meet these goals. By explicitly defining the constraints on sampling and by estimating the relationship between precision and bias of estimators and time spent counting, we can predict the optimal time at a point for each of several monitoring goals. In general, time spent at a point will differ depending on the goals of the study.

A Novel Multisensor Traffic State Assessment System Based on Incomplete Data

PubMed Central

Zeng, Yiliang; Lan, Jinhui; Ran, Bin; Jiang, Yaoliang

2014-01-01

A novel multisensor system with incomplete data is presented for traffic state assessment. The system comprises probe vehicle detection sensors, fixed detection sensors, and traffic state assessment algorithm. First of all, the validity checking of the traffic flow data is taken as preprocessing of this method. And then a new method based on the history data information is proposed to fuse and recover the incomplete data. According to the characteristics of space complementary of data based on the probe vehicle detector and fixed detector, a fusion model of space matching is presented to estimate the mean travel speed of the road. Finally, the traffic flow data include flow, speed and, occupancy rate, which are detected between Beijing Deshengmen bridge and Drum Tower bridge, are fused to assess the traffic state of the road by using the fusion decision model of rough sets and cloud. The accuracy of experiment result can reach more than 98%, and the result is in accordance with the actual road traffic state. This system is effective to assess traffic state, and it is suitable for the urban intelligent transportation system. PMID:25162055

Chip Based Magnetic Imager for Molecular Profiling of Ovarian Cancer Cells

DTIC Science & Technology

2016-12-01

2015) Genome-wide CRISPR screen in a mouse model of tumor growth and metastasis. Cell 160:1246-1260. PMC4380877, PMID:25748654. Acknowledgement of...Weissleder R, Lee H, Zhang F, Sharp PA (2015) Genome-wide CRISPR screen in a mouse model of tumor growth and metastasis. Cell 160:1246-1260. 5. Im H, Shao H...Lett 32(10):1229–1231. 6 of 6 | www.pnas.org/cgi/doi/10.1073/pnas.1501815112 Im et al. Resource Genome-wide CRISPR Screen in a Mouse Model of Tumor

Using a Novel Transgenic Mouse Model to Study c-Myc Oncogenic Pathway in Castration Resistance and Chemoresistance of Prostate Cancer

DTIC Science & Technology

2017-12-01

AWARD NUMBER: W81XWH-13-1-0162 TITLE: Using a Novel Transgenic Mouse Model to Study c-Myc Oncogenic Pathway in Castration Resistance and...DATES COVERED 15Sept2013 - 14Sept2017 4. TITLE AND SUBTITLE 5a. CONTRACT NUMBER Using a Novel Transgenic Mouse Model to Study c-Myc Oncogenic...for concisely studying castration response and CRPC. However, most mice never developed significant tumors. Here, we showed that ablation of p53 in this

Group prioritisation with unknown expert weights in incomplete linguistic context

NASA Astrophysics Data System (ADS)

Cheng, Dong; Cheng, Faxin; Zhou, Zhili; Wang, Juan

2017-09-01

In this paper, we study a group prioritisation problem in situations when the expert weights are completely unknown and their judgement preferences are linguistic and incomplete. Starting from the theory of relative entropy (RE) and multiplicative consistency, an optimisation model is provided for deriving an individual priority vector without estimating the missing value(s) of an incomplete linguistic preference relation. In order to address the unknown expert weights in the group aggregating process, we define two new kinds of expert weight indicators based on RE: proximity entropy weight and similarity entropy weight. Furthermore, a dynamic-adjusting algorithm (DAA) is proposed to obtain an objective expert weight vector and capture the dynamic properties involved in it. Unlike the extant literature of group prioritisation, the proposed RE approach does not require pre-allocation of expert weights and can solve incomplete preference relations. An interesting finding is that once all the experts express their preference relations, the final expert weight vector derived from the DAA is fixed irrespective of the initial settings of expert weights. Finally, an application example is conducted to validate the effectiveness and robustness of the RE approach.

Mouse Models for Drug Discovery. Can New Tools and Technology Improve Translational Power?

PubMed Central

Zuberi, Aamir; Lutz, Cathleen

2016-01-01

Abstract The use of mouse models in biomedical research and preclinical drug evaluation is on the rise. The advent of new molecular genome-altering technologies such as CRISPR/Cas9 allows for genetic mutations to be introduced into the germ line of a mouse faster and less expensively than previous methods. In addition, the rapid progress in the development and use of somatic transgenesis using viral vectors, as well as manipulations of gene expression with siRNAs and antisense oligonucleotides, allow for even greater exploration into genomics and systems biology. These technological advances come at a time when cost reductions in genome sequencing have led to the identification of pathogenic mutations in patient populations, providing unprecedented opportunities in the use of mice to model human disease. The ease of genetic engineering in mice also offers a potential paradigm shift in resource sharing and the speed by which models are made available in the public domain. Predictively, the knowledge alone that a model can be quickly remade will provide relief to resources encumbered by licensing and Material Transfer Agreements. For decades, mouse strains have provided an exquisite experimental tool to study the pathophysiology of the disease and assess therapeutic options in a genetically defined system. However, a major limitation of the mouse has been the limited genetic diversity associated with common laboratory mice. This has been overcome with the recent development of the Collaborative Cross and Diversity Outbred mice. These strains provide new tools capable of replicating genetic diversity to that approaching the diversity found in human populations. The Collaborative Cross and Diversity Outbred strains thus provide a means to observe and characterize toxicity or efficacy of new therapeutic drugs for a given population. The combination of traditional and contemporary mouse genome editing tools, along with the addition of genetic diversity in new modeling systems, are synergistic and serve to make the mouse a better model for biomedical research, enhancing the potential for preclinical drug discovery and personalized medicine. PMID:28053071

Dynamic Financial Constraints: Distinguishing Mechanism Design from Exogenously Incomplete Regimes*

PubMed Central

Karaivanov, Alexander; Townsend, Robert M.

2014-01-01

We formulate and solve a range of dynamic models of constrained credit/insurance that allow for moral hazard and limited commitment. We compare them to full insurance and exogenously incomplete financial regimes (autarky, saving only, borrowing and lending in a single asset). We develop computational methods based on mechanism design, linear programming, and maximum likelihood to estimate, compare, and statistically test these alternative dynamic models with financial/information constraints. Our methods can use both cross-sectional and panel data and allow for measurement error and unobserved heterogeneity. We estimate the models using data on Thai households running small businesses from two separate samples. We find that in the rural sample, the exogenously incomplete saving only and borrowing regimes provide the best fit using data on consumption, business assets, investment, and income. Family and other networks help consumption smoothing there, as in a moral hazard constrained regime. In contrast, in urban areas, we find mechanism design financial/information regimes that are decidedly less constrained, with the moral hazard model fitting best combined business and consumption data. We perform numerous robustness checks in both the Thai data and in Monte Carlo simulations and compare our maximum likelihood criterion with results from other metrics and data not used in the estimation. A prototypical counterfactual policy evaluation exercise using the estimation results is also featured. PMID:25246710

On incomplete sampling under birth-death models and connections to the sampling-based coalescent.

PubMed

Stadler, Tanja

2009-11-07

The constant rate birth-death process is used as a stochastic model for many biological systems, for example phylogenies or disease transmission. As the biological data are usually not fully available, it is crucial to understand the effect of incomplete sampling. In this paper, we analyze the constant rate birth-death process with incomplete sampling. We derive the density of the bifurcation events for trees on n leaves which evolved under this birth-death-sampling process. This density is used for calculating prior distributions in Bayesian inference programs and for efficiently simulating trees. We show that the birth-death-sampling process can be interpreted as a birth-death process with reduced rates and complete sampling. This shows that joint inference of birth rate, death rate and sampling probability is not possible. The birth-death-sampling process is compared to the sampling-based population genetics model, the coalescent. It is shown that despite many similarities between these two models, the distribution of bifurcation times remains different even in the case of very large population sizes. We illustrate these findings on an Hepatitis C virus dataset from Egypt. We show that the transmission times estimates are significantly different-the widely used Gamma statistic even changes its sign from negative to positive when switching from the coalescent to the birth-death process.

Mouse Model for the Preclinical Study of Metastatic Disease | NCI Technology Transfer Center | TTC

Cancer.gov

The Laboratory of Cancer Biology and Genetics, National Cancer Institute seeks partners for collaborative research to co-develop a mouse model that shows preclinical therapeutic response of residual metastatic disease.

Role of Growth Hormone in Prostate Cancer

DTIC Science & Technology

2007-02-01

syndrome produced by targeted disruption of the mouse growth hormone receptor/binding protein gene (the Laron mouse). Proc Natl Acad Sci USA 94:13215... Laron mouse, in which the gene coding for both GHR and GH binding protein has been disrupted or knocked out, with the C3(1)/Tag mouse, which develops...the Laron mouse). Nevertheless, the new model presented here demonstrates that the loss of GHR produced a significant reduction in the level of PIN in

Bat-mouse bone marrow chimera: a novel animal model for dissecting the uniqueness of the bat immune system.

PubMed

Yong, Kylie Su Mei; Ng, Justin Han Jia; Her, Zhisheng; Hey, Ying Ying; Tan, Sue Yee; Tan, Wilson Wei Sheng; Irac, Sergio Erdal; Liu, Min; Chan, Xue Ying; Gunawan, Merry; Foo, Randy Jee Hiang; Low, Dolyce Hong Wen; Mendenhall, Ian Hewitt; Chionh, Yok Teng; Dutertre, Charles-Antoine; Chen, Qingfeng; Wang, Lin-Fa

2018-03-16

Bats are an important animal model with long lifespans, low incidences of tumorigenesis and an ability to asymptomatically harbour pathogens. Currently, in vivo studies of bats are hampered due to their low reproduction rates. To overcome this, we transplanted bat cells from bone marrow (BM) and spleen into an immunodeficient mouse strain NOD-scid IL-2R -/- (NSG), and have successfully established stable, long-term reconstitution of bat immune cells in mice (bat-mice). Immune functionality of our bat-mouse model was demonstrated through generation of antigen-specific antibody response by bat cells following immunization. Post-engraftment of total bat BM cells and splenocytes, bat immune cells survived, expanded and repopulated the mouse without any observable clinical abnormalities. Utilizing bat's remarkable immunological functions, this novel model has a potential to be transformed into a powerful platform for basic and translational research.

Galantamine improves olfactory learning in the Ts65Dn mouse model of Down syndrome

PubMed Central

Simoes de Souza, Fabio M.; Busquet, Nicolas; Blatner, Megan; Maclean, Kenneth N.; Restrepo, Diego

2011-01-01

Down syndrome (DS) is the most common form of congenital intellectual disability. Although DS involves multiple disturbances in various tissues, there is little doubt that in terms of quality of life cognitive impairment is the most serious facet and there is no effective treatment for this aspect of the syndrome. The Ts65Dn mouse model of DS recapitulates multiple aspects of DS including cognitive impairment. Here the Ts65Dn mouse model of DS was evaluated in an associative learning paradigm based on olfactory cues. In contrast to disomic controls, trisomic mice exhibited significant deficits in olfactory learning. Treatment of trisomic mice with the acetylcholinesterase inhibitor galantamine resulted in a significant improvement in olfactory learning. Collectively, our study indicates that olfactory learning can be a sensitive tool for evaluating deficits in associative learning in mouse models of DS and that galantamine has therapeutic potential for improving cognitive abilities. PMID:22355654

Galantamine improves olfactory learning in the Ts65Dn mouse model of Down syndrome.

PubMed

de Souza, Fabio M Simoes; Busquet, Nicolas; Blatner, Megan; Maclean, Kenneth N; Restrepo, Diego

2011-01-01

Down syndrome (DS) is the most common form of congenital intellectual disability. Although DS involves multiple disturbances in various tissues, there is little doubt that in terms of quality of life cognitive impairment is the most serious facet and there is no effective treatment for this aspect of the syndrome. The Ts65Dn mouse model of DS recapitulates multiple aspects of DS including cognitive impairment. Here the Ts65Dn mouse model of DS was evaluated in an associative learning paradigm based on olfactory cues. In contrast to disomic controls, trisomic mice exhibited significant deficits in olfactory learning. Treatment of trisomic mice with the acetylcholinesterase inhibitor galantamine resulted in a significant improvement in olfactory learning. Collectively, our study indicates that olfactory learning can be a sensitive tool for evaluating deficits in associative learning in mouse models of DS and that galantamine has therapeutic potential for improving cognitive abilities.

A candidate model for Angelman syndrome in the mouse.

PubMed

Cattanach, B M; Barr, J A; Beechey, C V; Martin, J; Noebels, J; Jones, J

1997-07-01

Prader-Willi syndrome (PWS) and Angelman syndrome (AS) are well-recognized examples of imprinting in humans. They occur most commonly with paternal and maternal 15q11-13 deletions, but also with maternal and paternal disomy. Both syndromes have also occurred more rarely in association with smaller deletions seemingly causing abnormal imprinting. A putative mouse model of PWS, occurring with maternal duplication (partial maternal disomy) for the homologous region, has been described in a previous paper but, although a second imprinting effect that could have provided a mouse model of AS was found, it appeared to be associated with a slightly different region of the chromosome. Here, we provide evidence that the same region is in fact involved and further demonstrate that animals with paternal duplication for the region exhibit characteristics of AS patients. A mouse model of AS is, therefore, strongly indicated.

Development and testing of a mouse simulated space flight model

NASA Technical Reports Server (NTRS)

Sonnenfeld, Gerald

1987-01-01

The development and testing of a mouse model for simulating some aspects of weightlessness that occurs during space flight, and the carrying out of immunological experiments on animals undergoing space flight is examined. The mouse model developed was an antiorthostatic, hypokinetic, hypodynamic suspension model similar to one used with rats. The study was divided into two parts. The first involved determination of which immunological parameters should be observed on animals flown during space flight or studied in the suspension model. The second involved suspending mice and determining which of those immunological parameters were altered by the suspension. Rats that were actually flown in Space Shuttle SL-3 were used to test the hypotheses.

Multiple Drug Treatments That Increase cAMP Signaling Restore Long-Term Memory and Aberrant Signaling in Fragile X Syndrome Models.

PubMed

Choi, Catherine H; Schoenfeld, Brian P; Bell, Aaron J; Hinchey, Joseph; Rosenfelt, Cory; Gertner, Michael J; Campbell, Sean R; Emerson, Danielle; Hinchey, Paul; Kollaros, Maria; Ferrick, Neal J; Chambers, Daniel B; Langer, Steven; Sust, Steven; Malik, Aatika; Terlizzi, Allison M; Liebelt, David A; Ferreiro, David; Sharma, Ali; Koenigsberg, Eric; Choi, Richard J; Louneva, Natalia; Arnold, Steven E; Featherstone, Robert E; Siegel, Steven J; Zukin, R Suzanne; McDonald, Thomas V; Bolduc, Francois V; Jongens, Thomas A; McBride, Sean M J

2016-01-01

Fragile X is the most common monogenic disorder associated with intellectual disability (ID) and autism spectrum disorders (ASD). Additionally, many patients are afflicted with executive dysfunction, ADHD, seizure disorder and sleep disturbances. Fragile X is caused by loss of FMRP expression, which is encoded by the FMR1 gene. Both the fly and mouse models of fragile X are also based on having no functional protein expression of their respective FMR1 homologs. The fly model displays well defined cognitive impairments and structural brain defects and the mouse model, although having subtle behavioral defects, has robust electrophysiological phenotypes and provides a tool to do extensive biochemical analysis of select brain regions. Decreased cAMP signaling has been observed in samples from the fly and mouse models of fragile X as well as in samples derived from human patients. Indeed, we have previously demonstrated that strategies that increase cAMP signaling can rescue short term memory in the fly model and restore DHPG induced mGluR mediated long term depression (LTD) in the hippocampus to proper levels in the mouse model (McBride et al., 2005; Choi et al., 2011, 2015). Here, we demonstrate that the same three strategies used previously with the potential to be used clinically, lithium treatment, PDE-4 inhibitor treatment or mGluR antagonist treatment can rescue long term memory in the fly model and alter the cAMP signaling pathway in the hippocampus of the mouse model.

Distribution, density, and biomass of introduced small mammals in the southern mariana islands

USGS Publications Warehouse

Wiewel, A.S.; Adams, A.A.Y.; Rodda, G.H.

2009-01-01

Although it is generally accepted that introduced small mammals have detrimental effects on island ecology, our understanding of these effects is frequently limited by incomplete knowledge of small mammal distribution, density, and biomass. Such information is especially critical in the Mariana Islands, where small mammal density is inversely related to effectiveness of Brown Tree Snake (Boiga irregularis) control tools, such as mouse-attractant traps. We used mark-recapture sampling to determine introduced small mammal distribution, density, and biomass in the major habitats of Guam, Rota, Saipan, and Tinian, including grassland, Leucaena forest, and native limestone forest. Of the five species captured, Rattus diardii (sensu Robins et al. 2007) was most common across habitats and islands. In contrast, Mus musculus was rarely captured at forested sites, Suncus murinus was not captured on Rota, and R. exulans and R. norvegicus captures were uncommon. Modeling indicated that neophobia, island, sex, reproductive status, and rain amount influenced R. diardii capture probability, whereas time, island, and capture heterogeneity influenced S. murinus and M. musculus capture probability. Density and biomass were much greater on Rota, Saipan, and Tinian than on Guam, most likely a result of Brown Tree Snake predation pressure on the latter island. Rattus diardii and M. musculus density and biomass were greatest in grassland, whereas S. murinus density and biomass were greatest in Leucaena forest. The high densities documented during this research suggest that introduced small mammals (especially R. diardii) are impacting abundance and diversity of the native fauna and flora of the Mariana Islands. Further, Brown Tree Snake control and management tools that rely on mouse attractants will be less effective on Rota, Saipan, and Tinian than on Guam. If the Brown Tree Snake becomes established on these islands, high-density introduced small mammal populations will likely facilitate and support a high-density Brown Tree Snake population, even as native species are reduced or extirpated. ?? 2009 by University of Hawai'i Press All rights reserved.

On the Use of Gene Ontology Annotations to Assess Functional Similarity among Orthologs and Paralogs: A Short Report

PubMed Central

Thomas, Paul D.; Wood, Valerie; Mungall, Christopher J.; Lewis, Suzanna E.; Blake, Judith A.

2012-01-01

A recent paper (Nehrt et al., PLoS Comput. Biol. 7:e1002073, 2011) has proposed a metric for the “functional similarity” between two genes that uses only the Gene Ontology (GO) annotations directly derived from published experimental results. Applying this metric, the authors concluded that paralogous genes within the mouse genome or the human genome are more functionally similar on average than orthologous genes between these genomes, an unexpected result with broad implications if true. We suggest, based on both theoretical and empirical considerations, that this proposed metric should not be interpreted as a functional similarity, and therefore cannot be used to support any conclusions about the “ortholog conjecture” (or, more properly, the “ortholog functional conservation hypothesis”). First, we reexamine the case studies presented by Nehrt et al. as examples of orthologs with divergent functions, and come to a very different conclusion: they actually exemplify how GO annotations for orthologous genes provide complementary information about conserved biological functions. We then show that there is a global ascertainment bias in the experiment-based GO annotations for human and mouse genes: particular types of experiments tend to be performed in different model organisms. We conclude that the reported statistical differences in annotations between pairs of orthologous genes do not reflect differences in biological function, but rather complementarity in experimental approaches. Our results underscore two general considerations for researchers proposing novel types of analysis based on the GO: 1) that GO annotations are often incomplete, potentially in a biased manner, and subject to an “open world assumption” (absence of an annotation does not imply absence of a function), and 2) that conclusions drawn from a novel, large-scale GO analysis should whenever possible be supported by careful, in-depth examination of examples, to help ensure the conclusions have a justifiable biological basis. PMID:22359495

Dose-responsiveness and persistence of microRNA expression alterations induced by cigarette smoke in mouse lung.

PubMed

Izzotti, Alberto; Larghero, Patrizia; Longobardi, Mariagrazia; Cartiglia, Cristina; Camoirano, Anna; Steele, Vernon E; De Flora, Silvio

2011-12-01

Our previous studies demonstrated that exposure to cigarette smoke (CS), either mainstream or environmental, results in a remarkable downregulation of microRNA expression in the lung of both mice and rats. The goals of the present study were to evaluate the dose responsiveness to CS and the persistence of microRNA alterations after smoking cessation. ICR (CD-1) neonatal mice were exposed whole-body to mainstream CS, at the doses of 119, 292, 438, and 631mg/m(3) of total particulate matter. Exposure started within 12h after birth and continued daily for 4 weeks. The levels of bulky DNA adducts and 8-oxo-7,8-dihydro-2'-deoxyguanosine (8-oxodGuo) were measured by (32)P postlabeling procedures, and the expression of 697 mouse microRNAs was analyzed by microarray. The highest CS dose was lethal. Exposure to CS caused a dose-dependent increase of DNA alterations. DNA adducts and, even more sharply, 8-oxodGuo were reverted 1 and 4 weeks after smoking cessation. Exposure to CS resulted in an evident dysregulation of microRNA expression profiles, mainly in the sense of downregulation. The two lowest doses were not particularly effective, while the highest nonlethal dose produced extensive microRNA alterations. The expression of most downregulated microRNAs, including among others 7 members of the let-7 family, was restored one week after smoking cessation. However, the recovery was incomplete for a limited array of microRNAs, including mir-34b, mir-345, mir-421, mir-450b, mir-466, and mir-469. Thus, it appears that microRNAs mainly behave as biomarkers of effect and that exposure to high-dose, lasting for an adequate period of time, is needed to trigger the CS-related carcinogenesis process in the experimental animal model used. Copyright © 2011 Elsevier B.V. All rights reserved.

Intrinsic Lens Forming Potential of Mouse Lens Epithelial versus Newt Iris Pigment Epithelial Cells in Three-Dimensional Culture

PubMed Central

Nakamura, Kenta; Tsonis, Panagiotis A.

2014-01-01

Adult newts (Notophthalmus viridescens) are capable of complete lens regeneration that is mediated through dorsal iris pigment epithelial (IPE) cells transdifferentiation. In contrast, higher vertebrates such as mice demonstrate only limited lens regeneration in the presence of an intact lens capsule with remaining lens epithelial cells. To compare the intrinsic lens regeneration potential of newt IPE versus mouse lens epithelial cells (MLE), we have established a novel culture method that uses cell aggregation before culture in growth factor-reduced Matrigel™. Dorsal newt IPE aggregates demonstrated complete lens formation within 1 to 2 weeks of Matrigel culture without basic fibroblast growth factor (bFGF) supplementation, including the establishment of a peripheral cuboidal epithelial cell layer, and the appearance of central lens fibers that were positive for αA-crystallin. In contrast, the lens-forming potential of MLE cell aggregates cultured in Matrigel was incomplete and resulted in the formation of defined-size lentoids with partial optical transparency. While the peripheral cell layers of MLE aggregates were nucleated, cells in the center of aggregates demonstrated a nonapoptotic nuclear loss over a time period of 3 weeks that was representative of lens fiber formation. Matrigel culture supplementation with bFGF resulted in higher transparent bigger-size MLE aggregates that demonstrated increased appearance of βB1-crystallin expression. Our study demonstrates that bFGF is not required for induction of newt IPE aggregate-dependent lens formation in Matrigel, while the addition of bFGF seems to be beneficial for the formation of MLE aggregate-derived lens-like structures. In conclusion, the three-dimensional aggregate culture of IPE and MLE in Matrigel allows to a higher extent than older models the indepth study of the intrinsic lens-forming potential and the corresponding identification of lentogenic factors. PMID:23672748

The Virtual Mouse Brain: A Computational Neuroinformatics Platform to Study Whole Mouse Brain Dynamics.

PubMed

Melozzi, Francesca; Woodman, Marmaduke M; Jirsa, Viktor K; Bernard, Christophe

2017-01-01

Connectome-based modeling of large-scale brain network dynamics enables causal in silico interrogation of the brain's structure-function relationship, necessitating the close integration of diverse neuroinformatics fields. Here we extend the open-source simulation software The Virtual Brain (TVB) to whole mouse brain network modeling based on individual diffusion magnetic resonance imaging (dMRI)-based or tracer-based detailed mouse connectomes. We provide practical examples on how to use The Virtual Mouse Brain (TVMB) to simulate brain activity, such as seizure propagation and the switching behavior of the resting state dynamics in health and disease. TVMB enables theoretically driven experimental planning and ways to test predictions in the numerous strains of mice available to study brain function in normal and pathological conditions.

Monitoring blood-flow in the mouse cochlea using an endoscopic laser speckle contrast imaging system

PubMed Central

Yu, Sunkon; Jung, Byungjo; Choi, Jin Sil

2018-01-01

Laser speckle contrast imaging (LSCI) enables continuous high-resolution assessment of microcirculation in real-time. We applied an endoscope to LSCI to measure cochlear blood-flow in an ischemia–reperfusion mouse model. We also explored whether using xenon light in combination with LSCI facilitates visualization of anatomical position. Based on a previous preliminary study, the appropriate wavelength for penetrating the thin bony cochlea was 830 nm. A 2.7-mm-diameter endoscope was used, as appropriate for the size of the mouse cochlea. Our endoscopic LSCI system was used to illuminate the right cochlea after dissection of the mouse. We observed changes in the speckle signals when we applied the endoscopic LSCI system to the ischemia-reperfusion mouse model. The anatomical structure of the mouse cochlea and surrounding structures were clearly visible using the xenon light. The speckle signal of the cochlea was scattered, with an intensity that varied between that of the stapes (with the lowest signal), the negative control, and the stapedial artery (with the highest signal), the positive control. In the cochlear ischemia–reperfusion mouse model, the speckle signal of the cochlea decreased during the ischemic phase, and increased during the reperfusion phase, clearly reflecting cochlear blood-flow. The endoscopic LSCI system generates high-resolution images in real-time, allowing visualization of blood-flow and its changes in the mouse cochlea. Anatomical structures were clearly matched using LSCI along with visible light. PMID:29489849

Monitoring blood-flow in the mouse cochlea using an endoscopic laser speckle contrast imaging system.

PubMed

Kong, Tae Hoon; Yu, Sunkon; Jung, Byungjo; Choi, Jin Sil; Seo, Young Joon

2018-01-01

Laser speckle contrast imaging (LSCI) enables continuous high-resolution assessment of microcirculation in real-time. We applied an endoscope to LSCI to measure cochlear blood-flow in an ischemia-reperfusion mouse model. We also explored whether using xenon light in combination with LSCI facilitates visualization of anatomical position. Based on a previous preliminary study, the appropriate wavelength for penetrating the thin bony cochlea was 830 nm. A 2.7-mm-diameter endoscope was used, as appropriate for the size of the mouse cochlea. Our endoscopic LSCI system was used to illuminate the right cochlea after dissection of the mouse. We observed changes in the speckle signals when we applied the endoscopic LSCI system to the ischemia-reperfusion mouse model. The anatomical structure of the mouse cochlea and surrounding structures were clearly visible using the xenon light. The speckle signal of the cochlea was scattered, with an intensity that varied between that of the stapes (with the lowest signal), the negative control, and the stapedial artery (with the highest signal), the positive control. In the cochlear ischemia-reperfusion mouse model, the speckle signal of the cochlea decreased during the ischemic phase, and increased during the reperfusion phase, clearly reflecting cochlear blood-flow. The endoscopic LSCI system generates high-resolution images in real-time, allowing visualization of blood-flow and its changes in the mouse cochlea. Anatomical structures were clearly matched using LSCI along with visible light.

ANALYSIS OF TMEFF2 ALLOGRAFTS AND TRANSGENIC MOUSE MODELS REVEALS ROLES IN PROSTATE REGENERATION AND CANCER

PubMed Central

Corbin, JM.; Overcash, RF.; Wren, JD.; Coburn, A.; Tipton, GJ.; Ezzell, JA.; McNaughton, KK.; Fung, KM; Kosanke, SD.; Ruiz-Echevarria, MJ

2015-01-01

BACKGROUND Previous results from our lab indicate a tumor suppressor role for the transmembrane protein with epidermal growth factor and two follistatin motifs 2 (TMEFF2) in prostate cancer (PCa). Here, we further characterize this role and uncover new functions for TMEFF2 in cancer and adult prostate regeneration. METHODS The role of TMEFF2 was examined in PCa cells using Matrigel™ cultures and allograft models of PCa cells. In addition, we developed a transgenic mouse model that expresses TMEFF2 from a prostate specific promoter. Anatomical, histological and metabolic characterizations of the transgenic mouse prostate were conducted. The effect of TMEFF2 in prostate regeneration was studied by analyzing branching morphogenesis in the TMEFF2-expressing mouse lobes and alterations in branching morphogenesis were correlated with the metabolomic profiles of the mouse lobes. The role of TMEFF2 in prostate tumorigenesis in whole animals was investigated by crossing the TMEFF2 transgenic mice with the TRAMP mouse model of PCa and analyzing the histopathological changes in the progeny. RESULTS Ectopic expression of TMEFF2 impairs growth of PCa cells in Matrigel or allograft models. Surprisingly, while TMEFF2 expression in the TRAMP mouse did not have a significant effect on the glandular prostate epithelial lesions, the double TRAMP/TMEFF2 transgenic mice displayed an increased incidence of neuroendocrine type tumors. In addition, TMEFF2 promoted increased branching specifically in the dorsal lobe of the prostate suggesting a potential role in developmental processes. These results correlated with data indicating an alteration in the metabolic profile of the dorsal lobe of the transgenic TMEFF2 mice. CONCLUSIONS Collectively, our results confirm the tumor suppressor role of TMEFF2 and suggest that ectopic expression of TMEFF2 in mouse prostate leads to additional lobe-specific effects in prostate regeneration and tumorigenesis. This points to a complex and multifunctional role for TMEFF2 during PCa progression. PMID:26417683

Analysis of TMEFF2 allografts and transgenic mouse models reveals roles in prostate regeneration and cancer.

PubMed

Corbin, Joshua M; Overcash, Ryan F; Wren, Jonathan D; Coburn, Anita; Tipton, Greg J; Ezzell, Jennifer A; McNaughton, Kirk K; Fung, Kar-Ming; Kosanke, Stanley D; Ruiz-Echevarria, Maria J

2016-01-01

Previous results from our lab indicate a tumor suppressor role for the transmembrane protein with epidermal growth factor and two follistatin motifs 2 (TMEFF2) in prostate cancer (PCa). Here, we further characterize this role and uncover new functions for TMEFF2 in cancer and adult prostate regeneration. The role of TMEFF2 was examined in PCa cells using Matrigel(TM) cultures and allograft models of PCa cells. In addition, we developed a transgenic mouse model that expresses TMEFF2 from a prostate specific promoter. Anatomical, histological, and metabolic characterizations of the transgenic mouse prostate were conducted. The effect of TMEFF2 in prostate regeneration was studied by analyzing branching morphogenesis in the TMEFF2-expressing mouse lobes and alterations in branching morphogenesis were correlated with the metabolomic profiles of the mouse lobes. The role of TMEFF2 in prostate tumorigenesis in whole animals was investigated by crossing the TMEFF2 transgenic mice with the TRAMP mouse model of PCa and analyzing the histopathological changes in the progeny. Ectopic expression of TMEFF2 impairs growth of PCa cells in Matrigel or allograft models. Surprisingly, while TMEFF2 expression in the TRAMP mouse did not have a significant effect on the glandular prostate epithelial lesions, the double TRAMP/TMEFF2 transgenic mice displayed an increased incidence of neuroendocrine type tumors. In addition, TMEFF2 promoted increased branching specifically in the dorsal lobe of the prostate suggesting a potential role in developmental processes. These results correlated with data indicating an alteration in the metabolic profile of the dorsal lobe of the transgenic TMEFF2 mice. Collectively, our results confirm the tumor suppressor role of TMEFF2 and suggest that ectopic expression of TMEFF2 in mouse prostate leads to additional lobe-specific effects in prostate regeneration and tumorigenesis. This points to a complex and multifunctional role for TMEFF2 during PCa progression. © 2015 Wiley Periodicals, Inc.

Fuzzy portfolio model with fuzzy-input return rates and fuzzy-output proportions

NASA Astrophysics Data System (ADS)

Tsaur, Ruey-Chyn

2015-02-01

In the finance market, a short-term investment strategy is usually applied in portfolio selection in order to reduce investment risk; however, the economy is uncertain and the investment period is short. Further, an investor has incomplete information for selecting a portfolio with crisp proportions for each chosen security. In this paper we present a new method of constructing fuzzy portfolio model for the parameters of fuzzy-input return rates and fuzzy-output proportions, based on possibilistic mean-standard deviation models. Furthermore, we consider both excess or shortage of investment in different economic periods by using fuzzy constraint for the sum of the fuzzy proportions, and we also refer to risks of securities investment and vagueness of incomplete information during the period of depression economics for the portfolio selection. Finally, we present a numerical example of a portfolio selection problem to illustrate the proposed model and a sensitivity analysis is realised based on the results.

What do mouse models of muscular dystrophy tell us about the DAPC and its components?

PubMed

Whitmore, Charlotte; Morgan, Jennifer

2014-12-01

There are over 30 mouse models with mutations or inactivations in the dystrophin-associated protein complex. This complex is thought to play a crucial role in the functioning of muscle, as both a shock absorber and signalling centre, although its role in the pathogenesis of muscular dystrophy is not fully understood. The first mouse model of muscular dystrophy to be identified with a mutation in a component of the dystrophin-associated complex (dystrophin) was the mdx mouse in 1984. Here, we evaluate the key characteristics of the mdx in comparison with other mouse mutants with inactivations in DAPC components, along with key modifiers of the disease phenotype. By discussing the differences between the individual phenotypes, we show that the functioning of the DAPC and consequently its role in the pathogenesis is more complicated than perhaps currently appreciated. © 2014 The Authors. International Journal of Experimental Pathology © 2014 International Journal of Experimental Pathology.

Characterisation of a C1qtnf5 Ser163Arg Knock-In Mouse Model of Late-Onset Retinal Macular Degeneration

PubMed Central

Shu, Xinhua; Luhmann, Ulrich F. O.; Aleman, Tomas S.; Barker, Susan E.; Lennon, Alan; Tulloch, Brian; Chen, Mei; Xu, Heping; Jacobson, Samuel G.; Ali, Robin; Wright, Alan F.

2011-01-01

A single founder mutation resulting in a Ser163Arg substitution in the C1QTNF5 gene product causes autosomal dominant late-onset retinal macular degeneration (L-ORMD) in humans, which has clinical and pathological features resembling age-related macular degeneration. We generated and characterised a mouse “knock-in” model carrying the Ser163Arg mutation in the orthologous murine C1qtnf5 gene by site-directed mutagenesis and homologous recombination into mouse embryonic stem cells. Biochemical, immunological, electron microscopic, fundus autofluorescence, electroretinography and laser photocoagulation analyses were used to characterise the mouse model. Heterozygous and homozygous knock-in mice showed no significant abnormality in any of the above measures at time points up to 2 years. This result contrasts with another C1qtnf5 Ser163Arg knock-in mouse which showed most of the features of L-ORMD but differed in genetic background and targeting construct. PMID:22110650

Live dynamic imaging and analysis of developmental cardiac defects in mouse models with optical coherence tomography

NASA Astrophysics Data System (ADS)

Lopez, Andrew L.; Wang, Shang; Garcia, Monica; Valladolid, Christian; Larin, Kirill V.; Larina, Irina V.

2015-03-01

Understanding mouse embryonic development is an invaluable resource for our interpretation of normal human embryology and congenital defects. Our research focuses on developing methods for live imaging and dynamic characterization of early embryonic development in mouse models of human diseases. Using multidisciplinary methods: optical coherence tomography (OCT), live mouse embryo manipulations and static embryo culture, molecular biology, advanced image processing and computational modeling we aim to understand developmental processes. We have developed an OCT based approach to image live early mouse embryos (E8.5 - E9.5) cultured on an imaging stage and visualize developmental events with a spatial resolution of a few micrometers (less than the size of an individual cell) and a frame rate of up to hundreds of frames per second and reconstruct cardiodynamics in 4D (3D+time). We are now using these methods to study how specific embryonic lethal mutations affect cardiac morphology and function during early development.

Scattered Dose Calculations and Measurements in a Life-Like Mouse Phantom

PubMed Central

Welch, David; Turner, Leah; Speiser, Michael; Randers-Pehrson, Gerhard; Brenner, David J.

2017-01-01

Anatomically accurate phantoms are useful tools for radiation dosimetry studies. In this work, we demonstrate the construction of a new generation of life-like mouse phantoms in which the methods have been generalized to be applicable to the fabrication of any small animal. The mouse phantoms, with built-in density inhomogeneity, exhibit different scattering behavior dependent on where the radiation is delivered. Computer models of the mouse phantoms and a small animal irradiation platform were devised in Monte Carlo N-Particle code (MCNP). A baseline test replicating the irradiation system in a computational model shows minimal differences from experimental results from 50 Gy down to 0.1 Gy. We observe excellent agreement between scattered dose measurements and simulation results from X-ray irradiations focused at either the lung or the abdomen within our phantoms. This study demonstrates the utility of our mouse phantoms as measurement tools with the goal of using our phantoms to verify complex computational models. PMID:28140787

Overview of genetically engineered mouse models of colorectal carcinoma to enable translational biology and drug development.

PubMed

Roper, Jatin; Martin, Eric S; Hung, Kenneth E

2014-06-16

Preclinical models for colorectal cancer (CRC) are critical for translational biology and drug development studies to characterize and treat this condition. Mouse models of human cancer are particularly popular because of their relatively low cost, short life span, and ease of use. Genetically engineered mouse models (GEMMs) of CRC are engineered from germline or somatic modification of critical tumor suppressor genes and/or oncogenes that drive mutations in human disease. Detailed in this overview are the salient features of several useful colorectal cancer GEMMs and their value as tools for translational biology and preclinical drug development. Copyright © 2014 John Wiley & Sons, Inc.

Application of Mouse Models to Research in Hearing and Balance.

PubMed

Ohlemiller, Kevin K; Jones, Sherri M; Johnson, Kenneth R

2016-12-01

Laboratory mice (Mus musculus) have become the major model species for inner ear research. The major uses of mice include gene discovery, characterization, and confirmation. Every application of mice is founded on assumptions about what mice represent and how the information gained may be generalized. A host of successes support the continued use of mice to understand hearing and balance. Depending on the research question, however, some mouse models and research designs will be more appropriate than others. Here, we recount some of the history and successes of the use of mice in hearing and vestibular studies and offer guidelines to those considering how to apply mouse models.

Continuous imaging of the blood vessels in tumor mouse dorsal skin window chamber model by using SD-OCT

NASA Astrophysics Data System (ADS)

Peng, Xiao; Yang, Shaozhuang; Yu, Bin; Wang, Qi; Lin, Danying; Gao, Jian; Zhang, Peiqi; Ma, Yiqun; Qu, Junle; Niu, Hanben

2016-03-01

Optical Coherence Tomography (OCT) has been widely applied into microstructure imaging of tissues or blood vessels with a series of advantages, including non-destructiveness, real-time imaging, high resolution and high sensitivity. In this study, a Spectral Domain OCT (SD-OCT) system with higher sensitivity and signal-to-noise ratio (SNR) was built up, which was used to observe the blood vessel distribution and blood flow in the dorsal skin window chamber of the nude mouse tumor model. In order to obtain comparable data, the distribution images of blood vessels were collected from the same mouse before and after tumor injection. In conclusion, in vivo blood vessel distribution images of the tumor mouse model have been continuously obtained during around two weeks.

Graded Maximal Exercise Testing to Assess Mouse Cardio-Metabolic Phenotypes

PubMed Central

Petrosino, Jennifer M.; Heiss, Valerie J.; Maurya, Santosh K.; Kalyanasundaram, Anuradha; Periasamy, Muthu; LaFountain, Richard A.; Wilson, Jacob M.; Simonetti, Orlando P.; Ziouzenkova, Ouliana

2016-01-01

Functional assessments of cardiovascular fitness (CVF) are needed to establish animal models of dysfunction, test the effects of novel therapeutics, and establish the cardio-metabolic phenotype of mice. In humans, the graded maximal exercise test (GXT) is a standardized diagnostic for assessing CVF and mortality risk. These tests, which consist of concurrent staged increases in running speed and inclination, provide diagnostic cardio-metabolic parameters, such as, VO2max, anaerobic threshold, and metabolic crossover. Unlike the human-GXT, published mouse treadmill tests have set, not staged, increases in inclination as speed progress until exhaustion (PXT). Additionally, they often lack multiple cardio-metabolic parameters. Here, we developed a mouse-GXT with the intent of improving mouse-exercise testing sensitivity and developing translatable parameters to assess CVF in healthy and dysfunctional mice. The mouse-GXT, like the human-GXT, incorporated staged increases in inclination, speed, and intensity; and, was designed by considering imitations of the PXT and differences between human and mouse physiology. The mouse-GXT and PXTs were both tested in healthy mice (C57BL/6J, FVBN/J) to determine their ability to identify cardio-metabolic parameters (anaerobic threshold, VO2max, metabolic crossover) observed in human-GXTs. Next, theses assays were tested on established diet-induced (obese-C57BL/6J) and genetic (cardiac isoform Casq2-/-) models of cardiovascular dysfunction. Results showed that both tests reported VO2max and provided reproducible data about performance. Only the mouse-GXT reproducibly identified anaerobic threshold, metabolic crossover, and detected impaired CVF in dysfunctional models. Our findings demonstrated that the mouse-GXT is a sensitive, non-invasive, and cost-effective method for assessing CVF in mice. This new test can be used as a functional assessment to determine the cardio-metabolic phenotype of various animal models or the effects of novel therapeutics. PMID:26859763

Graded Maximal Exercise Testing to Assess Mouse Cardio-Metabolic Phenotypes.

PubMed

Petrosino, Jennifer M; Heiss, Valerie J; Maurya, Santosh K; Kalyanasundaram, Anuradha; Periasamy, Muthu; LaFountain, Richard A; Wilson, Jacob M; Simonetti, Orlando P; Ziouzenkova, Ouliana

2016-01-01

Functional assessments of cardiovascular fitness (CVF) are needed to establish animal models of dysfunction, test the effects of novel therapeutics, and establish the cardio-metabolic phenotype of mice. In humans, the graded maximal exercise test (GXT) is a standardized diagnostic for assessing CVF and mortality risk. These tests, which consist of concurrent staged increases in running speed and inclination, provide diagnostic cardio-metabolic parameters, such as, VO2max, anaerobic threshold, and metabolic crossover. Unlike the human-GXT, published mouse treadmill tests have set, not staged, increases in inclination as speed progress until exhaustion (PXT). Additionally, they often lack multiple cardio-metabolic parameters. Here, we developed a mouse-GXT with the intent of improving mouse-exercise testing sensitivity and developing translatable parameters to assess CVF in healthy and dysfunctional mice. The mouse-GXT, like the human-GXT, incorporated staged increases in inclination, speed, and intensity; and, was designed by considering imitations of the PXT and differences between human and mouse physiology. The mouse-GXT and PXTs were both tested in healthy mice (C57BL/6J, FVBN/J) to determine their ability to identify cardio-metabolic parameters (anaerobic threshold, VO2max, metabolic crossover) observed in human-GXTs. Next, theses assays were tested on established diet-induced (obese-C57BL/6J) and genetic (cardiac isoform Casq2-/-) models of cardiovascular dysfunction. Results showed that both tests reported VO2max and provided reproducible data about performance. Only the mouse-GXT reproducibly identified anaerobic threshold, metabolic crossover, and detected impaired CVF in dysfunctional models. Our findings demonstrated that the mouse-GXT is a sensitive, non-invasive, and cost-effective method for assessing CVF in mice. This new test can be used as a functional assessment to determine the cardio-metabolic phenotype of various animal models or the effects of novel therapeutics.

Bridging gaps: On the performance of airborne LiDAR to model wood mouse-habitat structure relationships in pine forests.

PubMed

Jaime-González, Carlos; Acebes, Pablo; Mateos, Ana; Mezquida, Eduardo T

2017-01-01

LiDAR technology has firmly contributed to strengthen the knowledge of habitat structure-wildlife relationships, though there is an evident bias towards flying vertebrates. To bridge this gap, we investigated and compared the performance of LiDAR and field data to model habitat preferences of wood mouse (Apodemus sylvaticus) in a Mediterranean high mountain pine forest (Pinus sylvestris). We recorded nine field and 13 LiDAR variables that were summarized by means of Principal Component Analyses (PCA). We then analyzed wood mouse's habitat preferences using three different models based on: (i) field PCs predictors, (ii) LiDAR PCs predictors; and (iii) both set of predictors in a combined model, including a variance partitioning analysis. Elevation was also included as a predictor in the three models. Our results indicate that LiDAR derived variables were better predictors than field-based variables. The model combining both data sets slightly improved the predictive power of the model. Field derived variables indicated that wood mouse was positively influenced by the gradient of increasing shrub cover and negatively affected by elevation. Regarding LiDAR data, two LiDAR PCs, i.e. gradients in canopy openness and complexity in forest vertical structure positively influenced wood mouse, although elevation interacted negatively with the complexity in vertical structure, indicating wood mouse's preferences for plots with lower elevations but with complex forest vertical structure. The combined model was similar to the LiDAR-based model and included the gradient of shrub cover measured in the field. Variance partitioning showed that LiDAR-based variables, together with elevation, were the most important predictors and that part of the variation explained by shrub cover was shared. LiDAR derived variables were good surrogates of environmental characteristics explaining habitat preferences by the wood mouse. Our LiDAR metrics represented structural features of the forest patch, such as the presence and cover of shrubs, as well as other characteristics likely including time since perturbation, food availability and predation risk. Our results suggest that LiDAR is a promising technology for further exploring habitat preferences by small mammal communities.

Ultrastructural study of Rift Valley fever virus in the mouse model

DOE Office of Scientific and Technical Information (OSTI.GOV)

Reed, Christopher; Steele, Keith E.; Honko, Anna

Detailed ultrastructural studies of Rift Valley fever virus (RVFV) in the mouse model are needed to develop and characterize a small animal model of RVF for the evaluation of potential vaccines and therapeutics. In this study, the ultrastructural features of RVFV infection in the mouse model were analyzed. The main changes in the liver included the presence of viral particles in hepatocytes and hepatic stem cells accompanied by hepatocyte apoptosis. However, viral particles were observed rarely in the liver; in contrast, particles were extremely abundant in the CNS. Despite extensive lymphocytolysis, direct evidence of viral replication was not observed inmore » the lymphoid tissue. These results correlate with the acute-onset hepatitis and delayed-onset encephalitis that are dominant features of severe human RVF, but suggest that host immune-mediated mechanisms contribute significantly to pathology. The results of this study expand our knowledge of RVFV-host interactions and further characterize the mouse model of RVF.« less

Diverse Application of Magnetic Resonance Imaging for Mouse Phenotyping

PubMed Central

Wu, Yijen L.; Lo, Cecilia W.

2017-01-01

Small animal models, particularly mouse models, of human diseases are becoming an indispensable tool for biomedical research. Studies in animal models have provided important insights into the etiology of diseases and accelerated the development of therapeutic strategies. Detailed phenotypic characterization is essential, both for the development of such animal models and mechanistic studies into disease pathogenesis and testing the efficacy of experimental therapeutics. Magnetic Resonance Imaging (MRI) is a versatile and non-invasive imaging modality with excellent penetration depth, tissue coverage, and soft tissue contrast. MRI, being a multi-modal imaging modality, together with proven imaging protocols and availability of good contrast agents, is ideally suited for phenotyping mutant mouse models. Here we describe the applications of MRI for phenotyping structural birth defects involving the brain, heart, and kidney in mice. The versatility of MRI and its ease of use are well suited to meet the rapidly increasing demands for mouse phenotyping in the coming age of functional genomics. PMID:28544650

A G542X cystic fibrosis mouse model for examining nonsense mutation directed therapies.

PubMed

McHugh, Daniel R; Steele, Miarasa S; Valerio, Dana M; Miron, Alexander; Mann, Rachel J; LePage, David F; Conlon, Ronald A; Cotton, Calvin U; Drumm, Mitchell L; Hodges, Craig A

2018-01-01

Nonsense mutations are present in 10% of patients with CF, produce a premature termination codon in CFTR mRNA causing early termination of translation, and lead to lack of CFTR function. There are no currently available animal models which contain a nonsense mutation in the endogenous Cftr locus that can be utilized to test nonsense mutation therapies. In this study, we create a CF mouse model carrying the G542X nonsense mutation in Cftr using CRISPR/Cas9 gene editing. The G542X mouse model has reduced Cftr mRNA levels, demonstrates absence of CFTR function, and displays characteristic manifestations of CF mice such as reduced growth and intestinal obstruction. Importantly, CFTR restoration is observed in G542X intestinal organoids treated with G418, an aminoglycoside with translational readthrough capabilities. The G542X mouse model provides an invaluable resource for the identification of potential therapies of CF nonsense mutations as well as the assessment of in vivo effectiveness of these potential therapies targeting nonsense mutations.

Humanized Mouse Models for the Study of Human Malaria Parasite Biology, Pathogenesis, and Immunity.

PubMed

Minkah, Nana K; Schafer, Carola; Kappe, Stefan H I

2018-01-01

Malaria parasite infection continues to inflict extensive morbidity and mortality in resource-poor countries. The insufficiently understood parasite biology, continuously evolving drug resistance and the lack of an effective vaccine necessitate intensive research on human malaria parasites that can inform the development of new intervention tools. Humanized mouse models have been greatly improved over the last decade and enable the direct study of human malaria parasites in vivo in the laboratory. Nevertheless, no small animal model developed so far is capable of maintaining the complete life cycle of Plasmodium parasites that infect humans. The ultimate goal is to develop humanized mouse systems in which a Plasmodium infection closely reproduces all stages of a parasite infection in humans, including pre-erythrocytic infection, blood stage infection and its associated pathology, transmission as well as the human immune response to infection. Here, we discuss current humanized mouse models and the future directions that should be taken to develop next-generation models for human malaria parasite research.

In utero mouse embryonic imaging with OCT for ophthalmologic research

NASA Astrophysics Data System (ADS)

Syed, Saba H.; Larina, Irina V.; Dickinson, Mary E.; Larin, Kirill V.

2011-03-01

Live imaging of an eye during embryonic development in mammalian model is important for understanding dynamic aspects of normal and abnormal eye morphogenesis. In this study, we used Swept Source Optical Coherence Tomography (SS-OCT) for live structural imaging of mouse embryonic eye through the uterine wall. The eye structure was reconstructed in mouse embryos at 13.5 to 17.5 days post coitus (dpc). Despite the limited imaging depth of OCT in turbid tissues, we were able to visualize the whole eye globe at these stages. These results suggest that live in utero OCT imaging is a useful tool to study embryonic eye development in the mouse model.

A physiologically based pharmacokinetic model for atrazine and its main metabolites in the adult male C57BL/6 mouse

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lin Zhoumeng; Interdisciplinary Toxicology Program, University of Georgia, Athens, GA 30602; Fisher, Jeffrey W.

Atrazine (ATR) is a chlorotriazine herbicide that is widely used and relatively persistent in the environment. In laboratory rodents, excessive exposure to ATR is detrimental to the reproductive, immune, and nervous systems. To better understand the toxicokinetics of ATR and to fill the need for a mouse model, a physiologically based pharmacokinetic (PBPK) model for ATR and its main chlorotriazine metabolites (Cl-TRIs) desethyl atrazine (DE), desisopropyl atrazine (DIP), and didealkyl atrazine (DACT) was developed for the adult male C57BL/6 mouse. Taking advantage of all relevant and recently made available mouse-specific data, a flow-limited PBPK model was constructed. The ATR andmore » DACT sub-models included blood, brain, liver, kidney, richly and slowly perfused tissue compartments, as well as plasma protein binding and red blood cell binding, whereas the DE and DIP sub-models were constructed as simple five-compartment models. The model adequately simulated plasma levels of ATR and Cl-TRIs and urinary dosimetry of Cl-TRIs at four single oral dose levels (250, 125, 25, and 5 mg/kg). Additionally, the model adequately described the dose dependency of brain and liver ATR and DACT concentrations. Cumulative urinary DACT amounts were accurately predicted across a wide dose range, suggesting the model's potential use for extrapolation to human exposures by performing reverse dosimetry. The model was validated using previously reported data for plasma ATR and DACT in mice and rats. Overall, besides being the first mouse PBPK model for ATR and its Cl-TRIs, this model, by analogy, provides insights into tissue dosimetry for rats. The model could be used in tissue dosimetry prediction and as an aid in the exposure assessment to this widely used herbicide.« less

Comparative mRNA analysis of behavioral and genetic mouse models of aggression.

PubMed

Malki, Karim; Tosto, Maria G; Pain, Oliver; Sluyter, Frans; Mineur, Yann S; Crusio, Wim E; de Boer, Sietse; Sandnabba, Kenneth N; Kesserwani, Jad; Robinson, Edward; Schalkwyk, Leonard C; Asherson, Philip

2016-04-01

Mouse models of aggression have traditionally compared strains, most notably BALB/cJ and C57BL/6. However, these strains were not designed to study aggression despite differences in aggression-related traits and distinct reactivity to stress. This study evaluated expression of genes differentially regulated in a stress (behavioral) mouse model of aggression with those from a recent genetic mouse model aggression. The study used a discovery-replication design using two independent mRNA studies from mouse brain tissue. The discovery study identified strain (BALB/cJ and C57BL/6J) × stress (chronic mild stress or control) interactions. Probe sets differentially regulated in the discovery set were intersected with those uncovered in the replication study, which evaluated differences between high and low aggressive animals from three strains specifically bred to study aggression. Network analysis was conducted on overlapping genes uncovered across both studies. A significant overlap was found with the genetic mouse study sharing 1,916 probe sets with the stress model. Fifty-one probe sets were found to be strongly dysregulated across both studies mapping to 50 known genes. Network analysis revealed two plausible pathways including one centered on the UBC gene hub which encodes ubiquitin, a protein well-known for protein degradation, and another on P38 MAPK. Findings from this study support the stress model of aggression, which showed remarkable molecular overlap with a genetic model. The study uncovered a set of candidate genes including the Erg2 gene, which has previously been implicated in different psychopathologies. The gene networks uncovered points at a Redox pathway as potentially being implicated in aggressive related behaviors. © 2016 Wiley Periodicals, Inc.

Posttransplant Intramuscular Injection of PLX-R18 Mesenchymal-Like Adherent Stromal Cells Improves Human Hematopoietic Engraftment in A Murine Transplant Model

PubMed Central

Metheny, Leland; Eid, Saada; Lingas, Karen; Ofir, Racheli; Pinzur, Lena; Meyerson, Howard; Lazarus, Hillard M.; Huang, Alex Y.

2018-01-01

Late-term complications of hematopoietic cell transplantation (HCT) are numerous and include incomplete engraftment. One possible mechanism of incomplete engraftment after HCT is cytokine-mediated suppression or dysfunction of the bone marrow microenvironment. Mesenchymal stromal cells (MSCs) elaborate cytokines that nurture or stimulate the marrow microenvironment by several mechanisms. We hypothesize that the administration of exogenous MSCs may modulate the bone marrow milieu and improve peripheral blood count recovery in the setting of incomplete engraftment. In the current study, we demonstrated that posttransplant intramuscular administration of human placental derived mesenchymal-like adherent stromal cells [PLacental eXpanded (PLX)-R18] harvested from a three-dimensional in vitro culture system improved posttransplant engraftment of human immune compartment in an immune-deficient murine transplantation model. As measured by the percentage of CD45+ cell recovery, we observed improvement in the peripheral blood counts at weeks 6 (8.4 vs. 24.1%, p < 0.001) and 8 (7.3 vs. 13.1%, p < 0.05) and in the bone marrow at week 8 (28 vs. 40.0%, p < 0.01) in the PLX-R18 cohort. As measured by percentage of CD19+ cell recovery, there was improvement at weeks 6 (12.6 vs. 3.8%) and 8 (10.1 vs. 4.1%). These results suggest that PLX-R18 may have a therapeutic role in improving incomplete engraftment after HCT. PMID:29520362

Posttransplant Intramuscular Injection of PLX-R18 Mesenchymal-Like Adherent Stromal Cells Improves Human Hematopoietic Engraftment in A Murine Transplant Model.

PubMed

Metheny, Leland; Eid, Saada; Lingas, Karen; Ofir, Racheli; Pinzur, Lena; Meyerson, Howard; Lazarus, Hillard M; Huang, Alex Y

2018-01-01

Late-term complications of hematopoietic cell transplantation (HCT) are numerous and include incomplete engraftment. One possible mechanism of incomplete engraftment after HCT is cytokine-mediated suppression or dysfunction of the bone marrow microenvironment. Mesenchymal stromal cells (MSCs) elaborate cytokines that nurture or stimulate the marrow microenvironment by several mechanisms. We hypothesize that the administration of exogenous MSCs may modulate the bone marrow milieu and improve peripheral blood count recovery in the setting of incomplete engraftment. In the current study, we demonstrated that posttransplant intramuscular administration of human placental derived mesenchymal-like adherent stromal cells [PLacental eXpanded (PLX)-R18] harvested from a three-dimensional in vitro culture system improved posttransplant engraftment of human immune compartment in an immune-deficient murine transplantation model. As measured by the percentage of CD45 + cell recovery, we observed improvement in the peripheral blood counts at weeks 6 (8.4 vs. 24.1%, p  < 0.001) and 8 (7.3 vs. 13.1%, p  < 0.05) and in the bone marrow at week 8 (28 vs. 40.0%, p  < 0.01) in the PLX-R18 cohort. As measured by percentage of CD19 + cell recovery, there was improvement at weeks 6 (12.6 vs. 3.8%) and 8 (10.1 vs. 4.1%). These results suggest that PLX-R18 may have a therapeutic role in improving incomplete engraftment after HCT.

The Dipeptidyl Peptidases 4, 8, and 9 in Mouse Monocytes and Macrophages: DPP8/9 Inhibition Attenuates M1 Macrophage Activation in Mice.

PubMed

Waumans, Yannick; Vliegen, Gwendolyn; Maes, Lynn; Rombouts, Miche; Declerck, Ken; Van Der Veken, Pieter; Vanden Berghe, Wim; De Meyer, Guido R Y; Schrijvers, Dorien; De Meester, Ingrid

2016-02-01

Atherosclerosis remains the leading cause of death in Western countries. Dipeptidyl peptidase (DPP) 4 has emerged as a novel target for the prevention and treatment of atherosclerosis. Family members DPP8 and 9 are abundantly present in macrophage-rich regions of atherosclerotic plaques, and DPP9 inhibition attenuates activation of human M1 macrophages in vitro. Studying this family in a mouse model for atherosclerosis would greatly advance our knowledge regarding their potential as therapeutic targets. We found that DPP4 is downregulated during mouse monocyte-to-macrophage differentiation. DPP8 and 9 expression seems relatively low in mouse monocytes and macrophages. Viability of primary mouse macrophages is unaffected by DPP4 or DPP8/9 inhibition. Importantly, DPP8/9 inhibition attenuates macrophage activation as IL-6 secretion is significantly decreased. Mouse macrophages respond similarly to DPP inhibition, compared to human macrophages. This shows that the mouse could become a valid model species for the study of DPPs as therapeutic targets in atherosclerosis.

Dyadic social interaction of C57BL/6 mice versus interaction with a toy mouse: conditioned place preference/aversion, substrain differences, and no development of a hierarchy.

PubMed

Pinheiro, Barbara S; Seidl, Simon S; Habazettl, Eva; Gruber, Bernadette E; Bregolin, Tanja; Zernig, Gerald

2016-04-01

Impaired social interaction is a hallmark symptom of many psychiatric diseases, including dependence syndromes (substance use disorders). Helping the addict reorient her/his behavior away from the drug of abuse toward social interaction would be of considerable therapeutic benefit. To study the neural basis of such a reorientation, we have developed several animal models in which the attractiveness of a dyadic (i.e. one-to-one) social interaction (DSI) can be compared directly with that of cocaine as a prototypical drug of abuse. Our models are based on the conditioned place preference (CPP) paradigm. In an ongoing effort to validate our experimental paradigms in C57BL/6 mice to make use of the plethora of transgenic models available in this genus, we found the following: (a) DSI with a live mouse produced CPP, whereas an interaction with an inanimate mouse-like object (i.e. a 'toy mouse'; toy mouse interaction) led to conditioned place aversion - but only in the Jackson substrain (C57BL/6J). (b) In the NIH substrain (C57BL/6N), both DSI and toy mouse interaction produced individual aversion in more than 50% of the tested mice. (c) Four 15 min DSI episodes did not result in the development of an observable hierarchy, that is, dominance/subordination behavior in the overwhelming majority (i.e. 30 of 32) of the tested Jackson mouse pairs. Therefore, dominance/subordination does not seem to be a confounding variable in our paradigm, at least not in C57BL/6J mice. Respective data for NIH mice were too limited to allow any conclusion. The present findings indicate that (a) DSI with a live mouse produces CPP to a greater degree than an interaction with an inanimate object resembling a mouse and that (b) certain substrain differences with respect to CPP/aversion to DSI do exist between the Jax and NIH substrain of C57BL/6 mice. These differences have to be considered when choosing a proper mouse substrain model for investigating the neural basis of DSI reward versus drug reward.

Quantitative volumetric imaging of normal, neoplastic and hyperplastic mouse prostate using ultrasound.

PubMed

Singh, Shalini; Pan, Chunliu; Wood, Ronald; Yeh, Chiuan-Ren; Yeh, Shuyuan; Sha, Kai; Krolewski, John J; Nastiuk, Kent L

2015-09-21

Genetically engineered mouse models are essential to the investigation of the molecular mechanisms underlying human prostate pathology and the effects of therapy on the diseased prostate. Serial in vivo volumetric imaging expands the scope and accuracy of experimental investigations of models of normal prostate physiology, benign prostatic hyperplasia and prostate cancer, which are otherwise limited by the anatomy of the mouse prostate. Moreover, accurate imaging of hyperplastic and tumorigenic prostates is now recognized as essential to rigorous pre-clinical trials of new therapies. Bioluminescent imaging has been widely used to determine prostate tumor size, but is semi-quantitative at best. Magnetic resonance imaging can determine prostate volume very accurately, but is expensive and has low throughput. We therefore sought to develop and implement a high throughput, low cost, and accurate serial imaging protocol for the mouse prostate. We developed a high frequency ultrasound imaging technique employing 3D reconstruction that allows rapid and precise assessment of mouse prostate volume. Wild-type mouse prostates were examined (n = 4) for reproducible baseline imaging, and treatment effects on volume were compared, and blinded data analyzed for intra- and inter-operator assessments of reproducibility by correlation and for Bland-Altman analysis. Examples of benign prostatic hyperplasia mouse model prostate (n = 2) and mouse prostate implantation of orthotopic human prostate cancer tumor and its growth (n =  ) are also demonstrated. Serial measurement volume of the mouse prostate revealed that high frequency ultrasound was very precise. Following endocrine manipulation, regression and regrowth of the prostate could be monitored with very low intra- and interobserver variability. This technique was also valuable to monitor the development of prostate growth in a model of benign prostatic hyperplasia. Additionally, we demonstrate accurate ultrasound image-guided implantation of orthotopic tumor xenografts and monitoring of subsequent tumor growth from ~10 to ~750 mm(3) volume. High frequency ultrasound imaging allows precise determination of normal, neoplastic and hyperplastic mouse prostate. Low cost and small image size allows incorporation of this imaging modality inside clean animal facilities, and thereby imaging of immunocompromised models. 3D reconstruction for volume determination is easily mastered, and both small and large relative changes in volume are accurately visualized. Ultrasound imaging does not rely on penetration of exogenous imaging agents, and so may therefore better measure poorly vascularized or necrotic diseased tissue, relative to bioluminescent imaging (IVIS). Our method is precise and reproducible with very low inter- and intra-observer variability. Because it is non-invasive, mouse models of prostatic disease states can be imaged serially, reducing inter-animal variability, and enhancing the power to detect small volume changes following therapeutic intervention.

Practical use of advanced mouse models for lung cancer.

PubMed

Safari, Roghaiyeh; Meuwissen, Ralph

2015-01-01

To date a variety of non-small cell lung cancer (NSCLC) and small cell lung cancer (SCLC) mouse models have been developed that mimic human lung cancer. Chemically induced or spontaneous lung cancer in susceptible inbred strains has been widely used, but the more recent genetically engineered somatic mouse models recapitulate much better the genotype-phenotype correlations found in human lung cancer. Additionally, improved orthotopic transplantation of primary human cancer tissue fragments or cells into lungs of immune-compromised mice can be valuable tools for preclinical research such as antitumor drug tests. Here we give a short overview of most somatic mouse models for lung cancer that are currently in use. We accompany each different model with a description of its practical use and application for all major lung tumor types, as well as the intratracheal injection or direct injection of fresh or freeze-thawed tumor cells or tumor cell lines into lung parenchyma of recipient mice. All here presented somatic mouse models are based on the ability to (in) activate specific alleles at a time, and in a tissue-specific cell type, of choice. This spatial-temporal controlled induction of genetic lesions allows the selective introduction of main genetic lesions in an adult mouse lung as found in human lung cancer. The resulting conditional somatic mouse models can be used as versatile powerful tools in basic lung cancer research and preclinical translational studies alike. These distinctively advanced lung cancer models permit us to investigate initiation (cell of origin) and progression of lung cancer, along with response and resistance to drug therapy. Cre/lox or FLP/frt recombinase-mediated methods are now well-used techniques to develop tissue-restricted lung cancer in mice with tumor-suppressor gene and/or oncogene (in)activation. Intranasal or intratracheal administration of engineered adenovirus-Cre or lentivirus-Cre has been optimized for introducing Cre recombinase activity into pulmonary tissues, and we discuss here the different techniques underlying these applications. Concomitant with Cre/Flp recombinase-based models are the tetracycline (Tet)-inducible bitransgenic systems in which presence or absence of doxycycline can turn the expression of a specific oncogene on or off. The use of several Tet-inducible lung cancer models for NSCLC is presented here in which the reversal of oncogene expression led to complete tumor regression and provided us with important insight of how oncogene dependence influence lung cancer survival and growth. As alternative to Tet-inducible models, we discuss the application of reversible expressed, transgenic mutant estrogen receptor (ER) fusion proteins, which are regulated via systemic tamoxifen administration. Most of the various lung cancer models can be combined through the generation of transgenic compound mice so that the use of these somatic mouse models can be even more enhanced for the study of specific molecular pathways that facilitate growth and maintenance of lung cancer. Finally, this description of the practical application and methodology of mouse models for lung cancer should be helpful in assisting researchers to make the best choices and optimal use of (existing) somatic models that suits the specific experimental needs in their study of lung cancer.

Massively Parallel Sequencing Reveals the Complex Structure of an Irradiated Human Chromosome on a Mouse Background in the Tc1 Model of Down Syndrome

PubMed Central

Clayton, Stephen; Prigmore, Elena; Langley, Elizabeth; Yang, Fengtang; Maguire, Sean; Fu, Beiyuan; Rajan, Diana; Sheppard, Olivia; Scott, Carol; Hauser, Heidi; Stephens, Philip J.; Stebbings, Lucy A.; Ng, Bee Ling; Fitzgerald, Tomas; Quail, Michael A.; Banerjee, Ruby; Rothkamm, Kai; Tybulewicz, Victor L. J.; Fisher, Elizabeth M. C.; Carter, Nigel P.

2013-01-01

Down syndrome (DS) is caused by trisomy of chromosome 21 (Hsa21) and presents a complex phenotype that arises from abnormal dosage of genes on this chromosome. However, the individual dosage-sensitive genes underlying each phenotype remain largely unknown. To help dissect genotype – phenotype correlations in this complex syndrome, the first fully transchromosomic mouse model, the Tc1 mouse, which carries a copy of human chromosome 21 was produced in 2005. The Tc1 strain is trisomic for the majority of genes that cause phenotypes associated with DS, and this freely available mouse strain has become used widely to study DS, the effects of gene dosage abnormalities, and the effect on the basic biology of cells when a mouse carries a freely segregating human chromosome. Tc1 mice were created by a process that included irradiation microcell-mediated chromosome transfer of Hsa21 into recipient mouse embryonic stem cells. Here, the combination of next generation sequencing, array-CGH and fluorescence in situ hybridization technologies has enabled us to identify unsuspected rearrangements of Hsa21 in this mouse model; revealing one deletion, six duplications and more than 25 de novo structural rearrangements. Our study is not only essential for informing functional studies of the Tc1 mouse but also (1) presents for the first time a detailed sequence analysis of the effects of gamma radiation on an entire human chromosome, which gives some mechanistic insight into the effects of radiation damage on DNA, and (2) overcomes specific technical difficulties of assaying a human chromosome on a mouse background where highly conserved sequences may confound the analysis. Sequence data generated in this study is deposited in the ENA database, Study Accession number: ERP000439. PMID:23596509

PREDICTIVE UNCERTAINTY IN HYDROLOGIC AND WATER QUALITY MODELING: APPROACHES, APPLICATION TO ENVIRONMENTAL MANAGEMENT, AND FUTURE CHALLENGES (PRESENTATION)

EPA Science Inventory

Extant process-based hydrologic and water quality models are indispensable to water resources planning and environmental management. However, models are only approximations of real systems and often calibrated with incomplete and uncertain data. Reliable estimates, or perhaps f...

PREDICTIVE UNCERTAINTY IN HYDROLOGIC AND WATER QUALITY MODELING: APPROACHES, APPLICATION TO ENVIRONMENTAL MANAGEMENT, AND FUTURE CHALLENGES

EPA Science Inventory

Extant process-based hydrologic and water quality models are indispensable to water resources planning and environmental management. However, models are only approximations of real systems and often calibrated with incomplete and uncertain data. Reliable estimates, or perhaps f...

eIF4E/Fmr1 double mutant mice display cognitive impairment in addition to ASD-like behaviors.

PubMed

Huynh, Thu N; Shah, Manan; Koo, So Yeon; Faraud, Kirsten S; Santini, Emanuela; Klann, Eric

2015-11-01

Autism spectrum disorder (ASD) is a group of heritable disorders with complex and unclear etiology. Classic ASD symptoms include social interaction and communication deficits as well as restricted, repetitive behaviors. In addition, ASD is often comorbid with intellectual disability. Fragile X syndrome (FXS) is the leading genetic cause of ASD, and is the most commonly inherited form of intellectual disability. Several mouse models of ASD and FXS exist, however the intellectual disability observed in ASD patients is not well modeled in mice. Using the Fmr1 knockout mouse and the eIF4E transgenic mouse, two previously characterized mouse models of fragile X syndrome and ASD, respectively, we generated the eIF4E/Fmr1 double mutant mouse. Our study shows that the eIF4E/Fmr1 double mutant mice display classic ASD behaviors, as well as cognitive dysfunction. Importantly, the learning impairments displayed by the double mutant mice spanned multiple cognitive tasks. Moreover, the eIF4E/Fmr1 double mutant mice display increased levels of basal protein synthesis. The results of our study suggest that the eIF4E/Fmr1 double mutant mouse may be a reliable model to study cognitive dysfunction in the context of ASD. Copyright © 2015 Elsevier Inc. All rights reserved.

Micro-CT Imaging Reveals Mekk3 Heterozygosity Prevents Cerebral Cavernous Malformations in Ccm2-Deficient Mice

PubMed Central

Choi, Jaesung P.; Foley, Matthew; Zhou, Zinan; Wong, Weng-Yew; Gokoolparsadh, Naveena; Arthur, J. Simon C.; Li, Dean Y.; Zheng, Xiangjian

2016-01-01

Mutations in CCM1 (aka KRIT1), CCM2, or CCM3 (aka PDCD10) gene cause cerebral cavernous malformation in humans. Mouse models of CCM disease have been established by deleting Ccm genes in postnatal animals. These mouse models provide invaluable tools to investigate molecular mechanism and therapeutic approaches for CCM disease. However, the full value of these animal models is limited by the lack of an accurate and quantitative method to assess lesion burden and progression. In the present study we have established a refined and detailed contrast enhanced X-ray micro-CT method to measure CCM lesion burden in mouse brains. As this study utilized a voxel dimension of 9.5μm (leading to a minimum feature size of approximately 25μm), it is therefore sufficient to measure CCM lesion volume and number globally and accurately, and provide high-resolution 3-D mapping of CCM lesions in mouse brains. Using this method, we found loss of Ccm1 or Ccm2 in neonatal endothelium confers CCM lesions in the mouse hindbrain with similar total volume and number. This quantitative approach also demonstrated a rescue of CCM lesions with simultaneous deletion of one allele of Mekk3. This method would enhance the value of the established mouse models to study the molecular basis and potential therapies for CCM and other cerebrovascular diseases. PMID:27513872

Incomplete Mixing and Reactions - A Lagrangian Approach in a Pure Shear Flow

NASA Astrophysics Data System (ADS)

Paster, A.; Aquino, T.; Bolster, D.

2014-12-01

Incomplete mixing of reactive solutes is well known to slow down reaction rates relative to what would be expected from assuming perfect mixing. As reactions progress in a system and deplete reactant concentrations, initial fluctuations in the concentrations of reactions can be amplified relative to mean background concentrations and lead to spatial segregation of reactants. As the system evolves, in the absence of sufficient mixing, this segregation will increase, leading to a persistence of incomplete mixing that fundamentally changes the effective rate at which overall reactions will progress. On the other hand, non-uniform fluid flows are known to affect mixing between interacting solutes. Thus a natural question arises: Can non-uniform flows sufficiently enhance mixing to suppress incomplete mixing effects, and if so, under what conditions? In this work we address this question by considering one of the simplest possible flows, a laminar pure shear flow, which is known to significantly enhance mixing relative to diffusion alone. To study this system we adapt a novel Lagrangian particle-based random walk method, originally designed to simulate reactions in purely diffusive systems, to the case of advection and diffusion in a shear flow. To interpret the results we develop a semi-analytical solution, by proposing a closure approximation that aims to capture the effect of incomplete mixing. The results obtained via the Lagrangian model and the semi-analytical solutions consistently highlight that if shear effects in the system are not sufficiently strong, incomplete mixing effects initially similar to purely diffusive systems will occur, slowing down the overall reaction rate. Then, at some later time, dependent on the strength of the shear, the system will return to behaving as if it were well-mixed, but represented by a reduced effective reaction rate. If shear effects are sufficiently strong, the incomplete mixing regime never emerges and the system can behave as well-mixed at all times.

Incomplete Mixing and Reactions - A Lagrangian Approach in a Pure Shear Flow

NASA Astrophysics Data System (ADS)

Paster, Amir; Bolster, Diogo; Aquino, Tomas

2015-04-01

Incomplete mixing of reactive solutes is well known to slow down reaction rates relative to what would be expected from assuming perfect mixing. As reactions progress in a system and deplete reactant concentrations, initial fluctuations in the concentrations of reactions can be amplified relative to mean background concentrations and lead to spatial segregation of reactants. As the system evolves, in the absence of sufficient mixing, this segregation will increase, leading to a persistence of incomplete mixing that fundamentally changes the effective rate at which overall reactions will progress. On the other hand, nonuniform fluid flows are known to affect mixing between interacting solutes. Thus a natural question arises: Can non-uniform flows sufficiently enhance mixing to suppress incomplete mixing effects, and if so, under what conditions? In this work we address this question by considering one of the simplest possible flows, a laminar pure shear flow, which is known to significantly enhance mixing relative to diffusion alone. To study this system we adapt a novel Lagrangian particle-based random walk method, originally designed to simulate reactions in purely diffusive systems, to the case of advection and diffusion in a shear flow. To interpret the results we develop a semi-analytical solution, by proposing a closure approximation that aims to capture the effect of incomplete mixing. The results obtained via the Lagrangian model and the semi-analytical solutions consistently highlight that if shear effects in the system are not sufficiently strong, incomplete mixing effects initially similar to purely diffusive systems will occur, slowing down the overall reaction rate. Then, at some later time, dependent on the strength of the shear, the system will return to behaving as if it were well-mixed, but represented by a reduced effective reaction rate. If shear effects are sufficiently strong, the incomplete mixing regime never emerges and the system can behave as well-mixed at all times.

The terminator mouse: salvation for primary cell culture.

PubMed

Kabgani, Nazanin; Moeller, Marcus J

2013-11-01

The Terminator had to come back from the future already several times in an effort to bring salvation to mankind. In the present issue of Kidney International, Guo et al. brought us a novel transgenic mouse model: the terminator mouse. This highly elegant mouse may facilitate significantly the derivation of primary cultures of a specific cell type from a tissue containing multiple cell populations.

Mouse Xenograft Model for Mesothelioma | NCI Technology Transfer Center | TTC

Cancer.gov

The National Cancer Institute is seeking parties interested in collaborative research to co-develop, evaluate, or commercialize a new mouse model for monoclonal antibodies and immunoconjugates that target malignant mesotheliomas. Applications of the technology include models for screening compounds as potential therapeutics for mesothelioma and for studying the pathology of mesothelioma.

HUPO BPP Workshop on Mouse Models for Neurodegeneration--Choosing the right models.

PubMed

Hamacher, Michael; Marcus, Katrin; Stephan, Christian; van Hall, Andre; Meyer, Helmut E

2005-09-01

The HUPO Brain Proteome Project met during the 4th Dutch Endo-Neuro-Psycho Meeting in Doorwerth, The Netherlands, on June 1, 2005, in order to discuss appropriate (mouse) models for neurodegenerative diseases as well as to conceptualise sophisticated proteomics analyses strategies. Here, the topics of the meeting are summarised.

Probabilistic failure assessment with application to solid rocket motors

NASA Technical Reports Server (NTRS)

Jan, Darrell L.; Davidson, Barry D.; Moore, Nicholas R.

1990-01-01

A quantitative methodology is being developed for assessment of risk of failure of solid rocket motors. This probabilistic methodology employs best available engineering models and available information in a stochastic framework. The framework accounts for incomplete knowledge of governing parameters, intrinsic variability, and failure model specification error. Earlier case studies have been conducted on several failure modes of the Space Shuttle Main Engine. Work in progress on application of this probabilistic approach to large solid rocket boosters such as the Advanced Solid Rocket Motor for the Space Shuttle is described. Failure due to debonding has been selected as the first case study for large solid rocket motors (SRMs) since it accounts for a significant number of historical SRM failures. Impact of incomplete knowledge of governing parameters and failure model specification errors is expected to be important.

AOM/DSS Model of Colitis-Associated Cancer

PubMed Central

Parang, Bobak; Barret, Caitlyn W.; Williams, Christopher S.

2016-01-01

Summary Our understanding of colitis-associated carcinoma (CAC) has benefited substantially from mouse models that faithfully recapitulate human CAC. Chemical models, in particular, have enabled fast and efficient analysis of genetic and environmental modulators of CAC without the added requirement of time-intensive genetic crossings. Here we describe the Azoxymethane (AOM)/Dextran Sodium Sulfate (DSS) mouse model of inflammatory colorectal cancer. PMID:27246042

Magnetic resonance imaging of amyloid plaques in transgenic mouse models of Alzheimer's disease

PubMed Central

Chamberlain, Ryan; Wengenack, Thomas M.; Poduslo, Joseph F.; Garwood, Michael; Jack, Clifford R.

2011-01-01

A major objective in the treatment of Alzheimer's disease is amyloid plaque reduction. Transgenic mouse models of Alzheimer's disease provide a controlled and consistent environment for studying amyloid plaque deposition in Alzheimer's disease. Magnetic resonance imaging is an attractive tool for longitudinal studies because it offers non-invasive monitoring of amyloid plaques. Recent studies have demonstrated the ability of magnetic resonance imaging to detect individual plaques in living mice. This review discusses the mouse models, MR pulse sequences, and parameters that have been used to image plaques and how they can be optimized for future studies. PMID:21499442

Standardization of deep partial-thickness scald burns in C57BL/6 mice

PubMed Central

Medina, Jorge L; Fourcaudot, Andrea B; Sebastian, Eliza A; Shankar, Ravi; Brown, Ammon W; Leung, Kai P

2018-01-01

Mouse burn models are used to understand the wound healing process and having a reproducible model is important. The different protocols used by researchers can lead to differences in depth of partial-thickness burn wounds. Additionally, standardizing a protocol for mouse burns in the laboratory for one strain may result in substantially different results in other strains. In our current study we describe the model development of a deep partial-thickness burn in C57BL/6 mice using hot water scalding as the source of thermal injury. As part of our model development we designed a template with specifications to allow for even contact of bare mouse skin (2×3 cm) with hot water while protecting the rest of the mouse. Burn depth was evaluated with H&E, Masson’s trichrome, and TUNEL staining. Final results were validated with pathology analysis. A water temperature of 54°C with a scalding time of 20 seconds produced consistent deep partial-thickness burns with available equipment described. Other than temperature and time, factors such as template materials and cooling steps after the burn could affect the uniformity of the burns. These findings are useful to burn research by providing some key parameters essential for researchers to simplify the development of their own mouse burn models. PMID:29755839

Physiologically Based Pharmacokinetic (PBPK) Modeling of Interstrain Variability in Trichloroethylene Metabolism in the Mouse

PubMed Central

Campbell, Jerry L.; Clewell, Harvey J.; Zhou, Yi-Hui; Wright, Fred A.; Guyton, Kathryn Z.

2014-01-01

Background: Quantitative estimation of toxicokinetic variability in the human population is a persistent challenge in risk assessment of environmental chemicals. Traditionally, interindividual differences in the population are accounted for by default assumptions or, in rare cases, are based on human toxicokinetic data. Objectives: We evaluated the utility of genetically diverse mouse strains for estimating toxicokinetic population variability for risk assessment, using trichloroethylene (TCE) metabolism as a case study. Methods: We used data on oxidative and glutathione conjugation metabolism of TCE in 16 inbred and 1 hybrid mouse strains to calibrate and extend existing physiologically based pharmacokinetic (PBPK) models. We added one-compartment models for glutathione metabolites and a two-compartment model for dichloroacetic acid (DCA). We used a Bayesian population analysis of interstrain variability to quantify variability in TCE metabolism. Results: Concentration–time profiles for TCE metabolism to oxidative and glutathione conjugation metabolites varied across strains. Median predictions for the metabolic flux through oxidation were less variable (5-fold range) than that through glutathione conjugation (10-fold range). For oxidative metabolites, median predictions of trichloroacetic acid production were less variable (2-fold range) than DCA production (5-fold range), although the uncertainty bounds for DCA exceeded the predicted variability. Conclusions: Population PBPK modeling of genetically diverse mouse strains can provide useful quantitative estimates of toxicokinetic population variability. When extrapolated to lower doses more relevant to environmental exposures, mouse population-derived variability estimates for TCE metabolism closely matched population variability estimates previously derived from human toxicokinetic studies with TCE, highlighting the utility of mouse interstrain metabolism studies for addressing toxicokinetic variability. Citation: Chiu WA, Campbell JL Jr, Clewell HJ III, Zhou YH, Wright FA, Guyton KZ, Rusyn I. 2014. Physiologically based pharmacokinetic (PBPK) modeling of interstrain variability in trichloroethylene metabolism in the mouse. Environ Health Perspect 122:456–463; http://dx.doi.org/10.1289/ehp.1307623 PMID:24518055

Postdoctoral Fellow | Center for Cancer Research

Cancer.gov

The Genetics of Cancer Susceptibility Section in the Mouse Cancer Genetics Program at NCI is seeking a highly motivated postdoctoral researcher to identify novel genetic interactors of BRCA2 using CRISPR-based genetic screen in mouse embryonic stem cells and perform functional studies in mouse models.

Early life exposure to bisphenol A investigated in mouse models of airway allergy, food allergy and oral tolerance.

PubMed

Nygaard, Unni Cecilie; Vinje, Nina Eriksen; Samuelsen, Mari; Andreassen, Monica; Groeng, Else-Carin; Bølling, Anette Kocbach; Becher, Rune; Lovik, Martinus; Bodin, Johanna

2015-09-01

The impact of early life exposure to bisphenol A (BPA) through drinking water was investigated in mouse models of respiratory allergy, food allergy and oral tolerance. Balb/c mice were exposed to BPA (0, 10 or 100 μg/ml), and the offspring were intranasally exposed to the allergen ovalbumin (OVA). C3H/HeJ offspring were sensitized with the food allergen lupin by intragastric gavage, after exposure to BPA (0, 1, 10 or 100 μg/ml). In separate offspring, oral tolerance was induced by gavage of 5 mg lupin one week before entering the protocol for the food allergy induction. In the airway allergy model, BPA (100 μg/ml) caused increased eosinophil numbers in bronchoalveolar lavage fluid (BALF) and a trend of increased OVA-specific IgE levels. In the food allergy and tolerance models, BPA did not alter the clinical anaphylaxis or antibody responses, but induced alterations in splenocyte cytokines and decreased mouse mast cell protease (MMCP)-1 serum levels. In conclusion, early life exposure to BPA through drinking water modestly augmented allergic responses in a mouse model of airway allergy only at high doses, and not in mouse models for food allergy and tolerance. Thus, our data do not support that BPA promotes allergy development at exposure levels relevant for humans. Copyright © 2015 Elsevier Ltd. All rights reserved.

New Rodent Population Models May Inform Human Health Risk Assessment and Identification of Genetic Susceptibility to Environmental Exposures.

PubMed

Harrill, Alison H; McAllister, Kimberly A

2017-08-15

This paper provides an introduction for environmental health scientists to emerging population-based rodent resources. Mouse reference populations provide an opportunity to model environmental exposures and gene-environment interactions in human disease and to inform human health risk assessment. This review will describe several mouse populations for toxicity assessment, including older models such as the Mouse Diversity Panel (MDP), and newer models that include the Collaborative Cross (CC) and Diversity Outbred (DO) models. This review will outline the features of the MDP, CC, and DO mouse models and will discuss published case studies investigating the use of these mouse population resources in each step of the risk assessment paradigm. These unique resources have the potential to be powerful tools for generating hypotheses related to gene-environment interplay in human disease, performing controlled exposure studies to understand the differential responses in humans for susceptibility or resistance to environmental exposures, and identifying gene variants that influence sensitivity to toxicity and disease states. These new resources offer substantial advances to classical toxicity testing paradigms by including genetically sensitive individuals that may inform toxicity risks for sensitive subpopulations. Both in vivo and complementary in vitro resources provide platforms with which to reduce uncertainty by providing population-level data around biological variability. https://doi.org/10.1289/EHP1274.

A Consensus Definition of Cataplexy in Mouse Models of Narcolepsy

PubMed Central

Scammell, Thomas E.; Willie, Jon T.; Guilleminault, Christian; Siegel, Jerome M.

2009-01-01

People with narcolepsy often have episodes of cataplexy, brief periods of muscle weakness triggered by strong emotions. Many researchers are now studying mouse models of narcolepsy, but definitions of cataplexy-like behavior in mice differ across labs. To establish a common language, the International Working Group on Rodent Models of Narcolepsy reviewed the literature on cataplexy in people with narcolepsy and in dog and mouse models of narcolepsy and then developed a consensus definition of murine cataplexy. The group concluded that murine cataplexy is an abrupt episode of nuchal atonia lasting at least 10 seconds. In addition, theta activity dominates the EEG during the episode, and video recordings document immobility. To distinguish a cataplexy episode from REM sleep after a brief awakening, at least 40 seconds of wakefulness must precede the episode. Bouts of cataplexy fitting this definition are common in mice with disrupted orexin/hypocretin signaling, but these events almost never occur in wild type mice. It remains unclear whether murine cataplexy is triggered by strong emotions or whether mice remain conscious during the episodes as in people with narcolepsy. This working definition provides helpful insights into murine cataplexy and should allow objective and accurate comparisons of cataplexy in future studies using mouse models of narcolepsy. Citation: Scammell TE; Willie JT; Guilleminault C; Siegel JM. A consensus definition of cataplexy in mouse models of narcolepsy. SLEEP 2009;32(1):111-116. PMID:19189786

New Rodent Population Models May Inform Human Health Risk Assessment and Identification of Genetic Susceptibility to Environmental Exposures

PubMed Central

Harrill, Alison H.

2017-01-01

Background: This paper provides an introduction for environmental health scientists to emerging population-based rodent resources. Mouse reference populations provide an opportunity to model environmental exposures and gene–environment interactions in human disease and to inform human health risk assessment. Objectives: This review will describe several mouse populations for toxicity assessment, including older models such as the Mouse Diversity Panel (MDP), and newer models that include the Collaborative Cross (CC) and Diversity Outbred (DO) models. Methods: This review will outline the features of the MDP, CC, and DO mouse models and will discuss published case studies investigating the use of these mouse population resources in each step of the risk assessment paradigm. Discussion: These unique resources have the potential to be powerful tools for generating hypotheses related to gene–environment interplay in human disease, performing controlled exposure studies to understand the differential responses in humans for susceptibility or resistance to environmental exposures, and identifying gene variants that influence sensitivity to toxicity and disease states. Conclusions: These new resources offer substantial advances to classical toxicity testing paradigms by including genetically sensitive individuals that may inform toxicity risks for sensitive subpopulations. Both in vivo and complementary in vitro resources provide platforms with which to reduce uncertainty by providing population-level data around biological variability. https://doi.org/10.1289/EHP1274 PMID:28886592

Hybrid liposomes showing enhanced accumulation in tumors as theranostic agents in the orthotopic graft model mouse of colorectal cancer.

PubMed

Okumura, Masaki; Ichihara, Hideaki; Matsumoto, Yoko

2018-11-01

Hybrid liposomes (HLs) can be prepared by simply sonicating a mixture of vesicular and micellar molecules in a buffer solution. This study aimed to elucidate the therapeutic effects and ability of HLs to detect (diagnosis) cancer in an orthotopic graft mouse model of colorectal cancer with HCT116 cells for the use of HLs as theranostic agents. In the absence of a chemotherapeutic drug, HLs exhibited therapeutic effects by inhibiting the growth of HCT116 colorectal cancer cells in vitro, possibly through an increase in apoptosis. Intravenously administered HLs also caused a remarkable reduction in the relative cecum weight in an orthotopic graft mouse model of colorectal cancer. A decrease in tumor size in the cecal sections was confirmed by histological analysis using HE staining. TUNEL staining indicated an induction of apoptosis in HCT116 cells in the orthotopic graft mouse model of colorectal cancer. For the detection (diagnosis) of colorectal cancer by HLs, the accumulation of HLs encapsulating a fluorescent probe (ICG) was observed in HCT116 cells in the in vivo colorectal cancer model following intravenous administration. These data indicate that HLs can accumulate in tumor cells in the cecum of the orthotopic graft mouse model of colorectal cancer for a prolonged period of time, and inhibit the growth of HCT116 cells.

Murine Models of Systemic Lupus Erythematosus

PubMed Central

Perry, Daniel; Sang, Allison; Yin, Yiming; Zheng, Ying-Yi; Morel, Laurence

2011-01-01

Systemic lupus erythematosus (SLE) is a multifactorial autoimmune disorder. The study of diverse mouse models of lupus has provided clues to the etiology of SLE. Spontaneous mouse models of lupus have led to identification of numerous susceptibility loci from which several candidate genes have emerged. Meanwhile, induced models of lupus have provided insight into the role of environmental factors in lupus pathogenesis as well as provided a better understanding of cellular mechanisms involved in the onset and progression of disease. The SLE-like phenotypes present in these models have also served to screen numerous potential SLE therapies. Due to the complex nature of SLE, it is necessary to understand the effect specific targeted therapies have on immune homeostasis. Furthermore, knowledge gained from mouse models will provide novel therapy targets for the treatment of SLE. PMID:21403825

CCL11 elicits secretion of RNases from mouse eosinophils and their cell-free granules

PubMed Central

Shamri, Revital; Melo, Rossana C. N.; Young, Kristen M.; Bivas-Benita, Maytal; Xenakis, Jason J.; Spencer, Lisa A.; Weller, Peter F.

2012-01-01

Rapid secretion of eosinophil-associated RNases (EARs), such as the human eosinophilic cationic protein (ECP), from intracellular granules is central to the role of eosinophils in allergic diseases and host immunity. Our knowledge regarding allergic inflammation has advanced based on mouse experimental models. However, unlike human eosinophils, capacities of mouse eosinophils to secrete granule proteins have been controversial. To study mechanisms of mouse eosinophil secretion and EAR release, we combined an RNase assay of mouse EARs with ultrastructural studies. In vitro, mouse eosinophils stimulated with the chemokine eotaxin-1 (CCL11) secreted enzymatically active EARs (EC50 5 nM) by piecemeal degranulation. In vivo, in a mouse model of allergic airway inflammation, increased airway eosinophil infiltration (24-fold) correlated with secretion of active RNases (3-fold). Moreover, we found that eosinophilic inflammation in mice can involve eosinophil cytolysis and release of cell-free granules. Cell-free mouse eosinophil granules expressed functional CCR3 receptors and secreted their granule proteins, including EAR and eosinophil peroxidase in response to CCL11. Collectively, these data demonstrate chemokine-dependent secretion of EARs from both intact mouse eosinophils and their cell-free granules, findings pertinent to understanding the pathogenesis of eosinophil-associated diseases, in which EARs are key factors.—Shamri, R., Melo, R. C. N., Young, K. M., B.-B, M., Xenakis, J. J., Spencer, L. A., Weller, P. F. CCL11 elicits secretion of RNases from mouse eosinophils and their cell-free granules. PMID:22294786

Predictors of seizure freedom after incomplete resection in children.

PubMed

Perry, M S; Dunoyer, C; Dean, P; Bhatia, S; Bavariya, A; Ragheb, J; Miller, I; Resnick, T; Jayakar, P; Duchowny, M

2010-10-19

Incomplete resection of the epileptogenic zone (EZ) is the most important predictor of poor outcome after resective surgery for intractable epilepsy. We analyzed the contribution of preoperative and perioperative variables including MRI and EEG data as predictors of seizure-free (SF) outcome after incomplete resection. We retrospectively reviewed patients <18 years of age with incomplete resection for epilepsy with 2 years of follow-up. Fourteen preoperative and perioperative variables were compared in SF and non-SF (NSF) patients. We compared lesional patients, categorized by reason for incompleteness, to lesional patients with complete resection. We analyzed for effect of complete EEG resection on SF outcome in patients with incompletely resected MRI lesions and vice versa. Eighty-three patients with incomplete resection were included with 41% becoming SF. Forty-eight lesional patients with complete resection were included. Thirty-eight percent (57/151) of patients with incomplete resection and 34% (47/138) with complete resection were excluded secondary to lack of follow-up or incomplete records. Contiguous MRI lesions were predictive of seizure freedom after incomplete resection. Fifty-seven percent of patients incomplete by MRI alone, 52% incomplete by EEG alone, and 24% incomplete by both became SF compared to 77% of patients with complete resection (p = 0.0005). Complete resection of the MRI- and EEG-defined EZ is the best predictor of seizure freedom, though patients incomplete by EEG or MRI alone have better outcome compared to patients incomplete by both. More than one-third of patients with incomplete resection become SF, with contiguous MRI lesions a predictor of SF outcome.

Multiple Drug Treatments That Increase cAMP Signaling Restore Long-Term Memory and Aberrant Signaling in Fragile X Syndrome Models

PubMed Central

Choi, Catherine H.; Schoenfeld, Brian P.; Bell, Aaron J.; Hinchey, Joseph; Rosenfelt, Cory; Gertner, Michael J.; Campbell, Sean R.; Emerson, Danielle; Hinchey, Paul; Kollaros, Maria; Ferrick, Neal J.; Chambers, Daniel B.; Langer, Steven; Sust, Steven; Malik, Aatika; Terlizzi, Allison M.; Liebelt, David A.; Ferreiro, David; Sharma, Ali; Koenigsberg, Eric; Choi, Richard J.; Louneva, Natalia; Arnold, Steven E.; Featherstone, Robert E.; Siegel, Steven J.; Zukin, R. Suzanne; McDonald, Thomas V.; Bolduc, Francois V.; Jongens, Thomas A.; McBride, Sean M. J.

2016-01-01

Fragile X is the most common monogenic disorder associated with intellectual disability (ID) and autism spectrum disorders (ASD). Additionally, many patients are afflicted with executive dysfunction, ADHD, seizure disorder and sleep disturbances. Fragile X is caused by loss of FMRP expression, which is encoded by the FMR1 gene. Both the fly and mouse models of fragile X are also based on having no functional protein expression of their respective FMR1 homologs. The fly model displays well defined cognitive impairments and structural brain defects and the mouse model, although having subtle behavioral defects, has robust electrophysiological phenotypes and provides a tool to do extensive biochemical analysis of select brain regions. Decreased cAMP signaling has been observed in samples from the fly and mouse models of fragile X as well as in samples derived from human patients. Indeed, we have previously demonstrated that strategies that increase cAMP signaling can rescue short term memory in the fly model and restore DHPG induced mGluR mediated long term depression (LTD) in the hippocampus to proper levels in the mouse model (McBride et al., 2005; Choi et al., 2011, 2015). Here, we demonstrate that the same three strategies used previously with the potential to be used clinically, lithium treatment, PDE-4 inhibitor treatment or mGluR antagonist treatment can rescue long term memory in the fly model and alter the cAMP signaling pathway in the hippocampus of the mouse model. PMID:27445731

Statistical methods for incomplete data: Some results on model misspecification.

PubMed

McIsaac, Michael; Cook, R J

2017-02-01

Inverse probability weighted estimating equations and multiple imputation are two of the most studied frameworks for dealing with incomplete data in clinical and epidemiological research. We examine the limiting behaviour of estimators arising from inverse probability weighted estimating equations, augmented inverse probability weighted estimating equations and multiple imputation when the requisite auxiliary models are misspecified. We compute limiting values for settings involving binary responses and covariates and illustrate the effects of model misspecification using simulations based on data from a breast cancer clinical trial. We demonstrate that, even when both auxiliary models are misspecified, the asymptotic biases of double-robust augmented inverse probability weighted estimators are often smaller than the asymptotic biases of estimators arising from complete-case analyses, inverse probability weighting or multiple imputation. We further demonstrate that use of inverse probability weighting or multiple imputation with slightly misspecified auxiliary models can actually result in greater asymptotic bias than the use of naïve, complete case analyses. These asymptotic results are shown to be consistent with empirical results from simulation studies.

Mouse Models as Predictors of Human Responses: Evolutionary Medicine.

PubMed

Uhl, Elizabeth W; Warner, Natalie J

Mice offer a number of advantages and are extensively used to model human diseases and drug responses. Selective breeding and genetic manipulation of mice have made many different genotypes and phenotypes available for research. However, in many cases, mouse models have failed to be predictive. Important sources of the prediction problem have been the failure to consider the evolutionary basis for species differences, especially in drug metabolism, and disease definitions that do not reflect the complexity of gene expression underlying disease phenotypes. Incorporating evolutionary insights into mouse models allow for unique opportunities to characterize the effects of diet, different gene expression profiles, and microbiomics underlying human drug responses and disease phenotypes.

Non-invasive detection of matrix-metalloproteinase activity in a mouse model of cerebral ischemia using multispectral optoacoustic tomography

NASA Astrophysics Data System (ADS)

Ni, Ruiqing; Vaas, Markus; Ren, Wuwei; Klohs, Jan

2018-02-01

Matrix metalloproteinases (MMPs) play important roles in the pathophysiology of cerebral ischemia. Here we visualized in vivo MMP activity in the transient middle cerebral artery occlusion (tMCAO) mouse model using multispectral optoacoustic imaging (MSOT) with a MMP-activatable probe. MSOT data was co-registered with structural magnetic resonance imaging (MRI) obtained at 7 T for localization of signal distribution. We demonstrated upregulated MMP signal within the focal ischemic lesion in the tMCAO mouse model using MSOT/MRI multimodal imaging. This convenient non-invasive method will allow repetitive measurement following the time course of MMP-lesion development in ischemic stroke animal model.

Autism Spectrum Disorders: Translating human deficits into mouse behavior.

PubMed

Pasciuto, E; Borrie, S C; Kanellopoulos, A K; Santos, A R; Cappuyns, E; D'Andrea, L; Pacini, L; Bagni, C

2015-10-01

Autism Spectrum Disorders are a heterogeneous group of neurodevelopmental disorders, with rising incidence but little effective therapeutic intervention available. Currently two main clinical features are described to diagnose ASDs: impaired social interaction and communication, and repetitive behaviors. Much work has focused on understanding underlying causes of ASD by generating animal models of the disease, in the hope of discovering signaling pathways and cellular targets for drug intervention. Here we review how ASD behavioral phenotypes can be modeled in the mouse, the most common animal model currently in use in this field, and discuss examples of genetic mouse models of ASD with behavioral features that recapitulate various symptoms of ASD. Copyright © 2015 Elsevier Inc. All rights reserved.

Mouse models of ciliopathies: the state of the art

PubMed Central

Norris, Dominic P.; Grimes, Daniel T.

2012-01-01

The ciliopathies are an apparently disparate group of human diseases that all result from defects in the formation and/or function of cilia. They include disorders such as Meckel-Grüber syndrome (MKS), Joubert syndrome (JBTS), Bardet-Biedl syndrome (BBS) and Alström syndrome (ALS). Reflecting the manifold requirements for cilia in signalling, sensation and motility, different ciliopathies exhibit common elements. The mouse has been used widely as a model organism for the study of ciliopathies. Although many mutant alleles have proved lethal, continued investigations have led to the development of better models. Here, we review current mouse models of a core set of ciliopathies, their utility and future prospects. PMID:22566558

Barriers to childhood immunisation: Findings from the Longitudinal Study of Australian Children.

PubMed

Pearce, Anna; Marshall, Helen; Bedford, Helen; Lynch, John

2015-06-26

To examine barriers to childhood immunisation experienced by parents in Australia. Cross-sectional analysis of secondary data. Nationally representative Longitudinal Study of Australian Children (LSAC). Five thousand one hundred seven infants aged 3-19 months in 2004. Maternal report of immunisation status: incompletely or fully immunised. Overall, 9.3% (473) of infants were incompletely immunised; of these just 16% had mothers who disagreed with immunisation. Remaining analyses focussed on infants whose mother did not disagree with immunisation (N=4994) (of whom 8% [398] were incompletely immunised). Fifteen variables representing potential immunisation barriers and facilitators were available in LSAC; these were entered into a latent class model to identify distinct clusters (or 'classes') of barriers experienced by families. Five classes were identified: (1) 'minimal barriers', (2) 'lone parent, mobile families with good support', (3) 'low social contact and service information; psychological distress', (4) 'larger families, not using formal childcare', (5) 'child health issues/concerns'. Compared to infants from families experiencing minimal barriers, all other barrier classes had a higher risk of incomplete immunisation. For example, the adjusted risk ratio (RR) for incomplete immunisation was 1.51 (95% confidence interval: 1.08-2.10) among those characterised by 'low social contact and service information; psychological distress', and 2.47 (1.87-3.25) among 'larger families, not using formal childcare'. Using the most recent data available for examining these issues in Australia, we found that the majority of incompletely immunised infants (in 2004) did not have a mother who disagreed with immunisation. Barriers to immunisation are heterogeneous, suggesting a need for tailored interventions. Copyright © 2015 The Authors. Published by Elsevier Ltd.. All rights reserved.

Groundwater withdrawals under drought: reconciling GRACE and land surface models in the United States High Plains Aquifer

USDA-ARS?s Scientific Manuscript database

Advanced Land Surface Models (LSM) offer a powerful tool for studying hydrological variability. Highly managed systems, however, present a challenge for these models, which typically have simplified or incomplete representations of human water use. Here we examine recent groundwater declines in the ...

Effect of social odor context on the emission of isolation-induced ultrasonic vocalizations in the BTBR T+tf/J mouse model for autism

PubMed Central

Wöhr, Markus

2015-01-01

An important diagnostic criterion for social communication deficits in autism spectrum disorders (ASD) are difficulties in adjusting behavior to suit different social contexts. While the BTBR T+tf/J (BTBR) inbred strain of mice is one of the most commonly used mouse models for ASD, little is known about whether BTBR mice display deficits in detecting changes in social context and their ability to adjust to them. Here, it was tested therefore whether the emission of isolation-induced ultrasonic vocalizations (USV) in BTBR mouse pups is affected by the social odor context, in comparison to the standard control strain with high sociability, C57BL/6J (B6). It is known that the presence of odors from mothers and littermates leads to a calming of the isolated mouse pup, and hence to a reduction in isolation-induced USV emission. In accordance with their behavioral phenotypes with relevance to all diagnostic core symptoms of ASD, it was predicted that BTBR mouse pups would not display a calming response when tested under soiled bedding conditions with home cage bedding material containing maternal odors, and that similar isolation-induced USV emission rates would be seen in BTBR mice tested under clean and soiled bedding conditions. Unexpectedly, however, the present findings show that BTBR mouse pups display such a calming response and emit fewer isolation-induced USV when tested under soiled as compared to clean bedding conditions, similar to B6 mouse pups. Yet, in contrast to B6 mouse pups, which emitted isolation-induced USV with shorter call durations and lower levels of frequency modulation under soiled bedding conditions, social odor context had no effect on acoustic call features in BTBR mouse pups. This indicates that the BTBR mouse model for ASD does not display deficits in detecting changes in social context, but has a limited ability and/or reduced motivation to adjust to them. PMID:25852455

A Bayesian statistical analysis of mouse dermal tumor promotion assay data for evaluating cigarette smoke condensate.

PubMed

Kathman, Steven J; Potts, Ryan J; Ayres, Paul H; Harp, Paul R; Wilson, Cody L; Garner, Charles D

2010-10-01

The mouse dermal assay has long been used to assess the dermal tumorigenicity of cigarette smoke condensate (CSC). This mouse skin model has been developed for use in carcinogenicity testing utilizing the SENCAR mouse as the standard strain. Though the model has limitations, it remains as the most relevant method available to study the dermal tumor promoting potential of mainstream cigarette smoke. In the typical SENCAR mouse CSC bioassay, CSC is applied for 29 weeks following the application of a tumor initiator such as 7,12-dimethylbenz[a]anthracene (DMBA). Several endpoints are considered for analysis including: the percentage of animals with at least one mass, latency, and number of masses per animal. In this paper, a relatively straightforward analytic model and procedure is presented for analyzing the time course of the incidence of masses. The procedure considered here takes advantage of Bayesian statistical techniques, which provide powerful methods for model fitting and simulation. Two datasets are analyzed to illustrate how the model fits the data, how well the model may perform in predicting data from such trials, and how the model may be used as a decision tool when comparing the dermal tumorigenicity of cigarette smoke condensate from multiple cigarette types. The analysis presented here was developed as a statistical decision tool for differentiating between two or more prototype products based on the dermal tumorigenicity. Copyright (c) 2010 Elsevier Inc. All rights reserved.

Validation of the Glaucoma Filtration Surgical Mouse Model for Antifibrotic Drug Evaluation

PubMed Central

Seet, Li-Fong; Lee, Wing Sum; Su, Roseline; Finger, Sharon N; Crowston, Jonathan G; Wong, Tina T

2011-01-01

Glaucoma is a progressive optic neuropathy, which, if left untreated, leads to blindness. The most common and most modifiable risk factor in glaucoma is elevated intraocular pressure (IOP), which can be managed surgically by filtration surgery. The postoperative subconjunctival scarring response, however, remains the major obstacle to achieving long-term surgical success. Antiproliferatives such as mitomycin C are commonly used to prevent postoperative scarring. Efficacy of these agents has been tested extensively on monkey and rabbit models of glaucoma filtration surgery. As these models have inherent limitations, we have developed a model of glaucoma filtration surgery in the mouse. We show, for the first time, that the mouse model typically scarred within 14 d, but when augmented with mitomycin C, more animals maintained lower intraocular pressures for a longer period of time concomitant with prolonged bleb survival to beyond 28 d. The morphology of the blebs following mitomycin C treatment also resembled well-documented clinical observations, thus confirming the validity and clinical relevance of this model. We demonstrate that the antiscarring response to mitomycin C is likely to be due to its effects on conjunctival fibroblast proliferation, apoptosis and collagen deposition and the suppression of inflammation. Indeed, we verified some of these properties on mouse conjunctival fibroblasts cultured in vitro. These data support the suitability of this mouse model for studying the wound healing response in glaucoma filtration surgery, and as a potentially useful tool for the in vivo evaluation of antifibrotic therapeutics in the eye. PMID:21229189

Mouse Vocal Communication System: Are Ultrasounds Learned or Innate?

ERIC Educational Resources Information Center

Arriaga, Gustavo; Jarvis, Erich D.

2013-01-01

Mouse ultrasonic vocalizations (USVs) are often used as behavioral readouts of internal states, to measure effects of social and pharmacological manipulations, and for behavioral phenotyping of mouse models for neuropsychiatric and neurodegenerative disorders. However, little is known about the neurobiological mechanisms of rodent USV production.…

CURRENT METHODS AND RESEARCH STRATEGIES FOR MODELING ATMOSPHERIC MERCURY

EPA Science Inventory

The atmospheric pathway of the global mercury cycle is known to be the primary source of mercury contamination to most threatened aquatic ecosystems. Current efforts toward numerical modeling of atmospheric mercury are hindered by an incomplete understanding of emissions, atmosp...

Localization, structure and polymorphism of two paralogous Xenopus laevis mitochondrial malate dehydrogenase genes.

PubMed

Tlapakova, Tereza; Krylov, Vladimir; Macha, Jaroslav

2005-01-01

Two paralogous mitochondrial malate dehydrogenase 2 (Mdh2) genes of Xenopus laevis have been cloned and sequenced, revealing 95% identity. Fluorescence in-situ hybridization (FISH) combined with tyramide amplification discriminates both genes; Mdh2a was localized into chromosome q3 and Mdh2b into chromosome q8. One kb cDNA probes detect both genes with 85% accuracy. The remaining signals were on the paralogous counterpart. Introns interrupt coding sequences at the same nucleotide as defined for mouse. Restriction polymorphism has been detected in the first intron of Mdh2a, while the individual variability in intron 6 of Mdh2b gene is represented by an insertion of incomplete retrotransposon L1Xl. Rates of nucleotide substitutions indicate that both genes are under similar evolutionary constraints. X. laevis Mdh2 genes can be used as markers for physical mapping and linkage analysis.

The Proteome Folding Project: Proteome-scale prediction of structure and function

PubMed Central

Drew, Kevin; Winters, Patrick; Butterfoss, Glenn L.; Berstis, Viktors; Uplinger, Keith; Armstrong, Jonathan; Riffle, Michael; Schweighofer, Erik; Bovermann, Bill; Goodlett, David R.; Davis, Trisha N.; Shasha, Dennis; Malmström, Lars; Bonneau, Richard

2011-01-01

The incompleteness of proteome structure and function annotation is a critical problem for biologists and, in particular, severely limits interpretation of high-throughput and next-generation experiments. We have developed a proteome annotation pipeline based on structure prediction, where function and structure annotations are generated using an integration of sequence comparison, fold recognition, and grid-computing-enabled de novo structure prediction. We predict protein domain boundaries and three-dimensional (3D) structures for protein domains from 94 genomes (including human, Arabidopsis, rice, mouse, fly, yeast, Escherichia coli, and worm). De novo structure predictions were distributed on a grid of more than 1.5 million CPUs worldwide (World Community Grid). We generated significant numbers of new confident fold annotations (9% of domains that are otherwise unannotated in these genomes). We demonstrate that predicted structures can be combined with annotations from the Gene Ontology database to predict new and more specific molecular functions. PMID:21824995

"Isogaba Maware": quality control of genome DNA by checkpoints.

PubMed

Kitazono, A; Matsumoto, T

1998-05-01

Checkpoints maintain the interdependency of cell cycle events by permitting the onset of an event only after the completion of the preceding event. The DNA replication checkpoint induces a cell cycle arrest until the completion of the DNA replication. Similarly, the DNA damage checkpoint arrests cell cycle progression if DNA repair is incomplete. A number of genes that play a role in the two checkpoints have been identified through genetic studies in yeasts, and their homologues have been found in fly, mouse, and human. They form signaling cascades activated by a DNA replication block or DNA damage and subsequently generate the negative constraints on cell cycle regulators. The failure of these signaling cascades results in producing offspring that carry mutations or that lack a portion of the genome. In humans, defects in the checkpoints are often associated with cancer-prone diseases. Focusing mainly on the studies in budding and fission yeasts, we summarize the recent progress.

Zinc and Zinc Transporters: Novel Regulators of Ventricular Myocardial Development.

PubMed

Lin, Wen; Li, Deqiang

2018-06-01

Ventricular myocardial development is a well-orchestrated process involving different cardiac structures, multiple signal pathways, and myriad proteins. Dysregulation of this important developmental event can result in cardiomyopathies, such as left ventricle non-compaction, which affect the pediatric population and the adults. Human and mouse studies have shed light upon the etiology of some cardiomyopathy cases and highlighted the contribution of both genetic and environmental factors. However, the regulation of ventricular myocardial development remains incompletely understood. Zinc is an essential trace metal with structural, enzymatic, and signaling function. Perturbation of zinc homeostasis has resulted in developmental and physiological defects including cardiomyopathy. In this review, we summarize several mechanisms by which zinc and zinc transporters can impact the regulation of ventricular myocardial development. Based on our review, we propose that zinc deficiency and mutations of zinc transporters may underlie some cardiomyopathy cases especially those involving ventricular myocardial development defects.

Radiation induced abnormalities in early in vitro mouse embryos

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kirkpatrick, J.F.

1973-08-01

Female mice were superovulated and mated, and the two-cell embryos were collected and cultured in vitro. The embryos were exposed to x-irradiation (0 to 491 rads) during the two-cell stage before the appearance of the next cleavage plate, placed in new unirradiated culture medium and observed during subsequent development. Morphological abnormalities, which occurred as a result of irradiation, included fragmentation, disintegration, granlation, incomplete cleavage, cleavage cessation, nuclear degeneration and pycnosis and cytoplasmic vacuolization. There was no damage to the zona pellucida. The types of abnormalities indicate an agreement with the results of previous in vivo studies. A distinct correlation existedmore » between morphological abnormalities and embryo death. The greatest number of abnormalities resulted within five hours following irradiation, but increased through 20 hours post-exposure. At doses above 300 rads, the magnitude of damage was greater in the in vitro embryos than that shown in previous in vivo studies. (auth)« less

Smallpox virus plaque phenotypes: genetic, geographical and case fatality relationships.

PubMed

Olson, Victoria A; Karem, Kevin L; Smith, Scott K; Hughes, Christine M; Damon, Inger K

2009-04-01

Smallpox (infection with Orthopoxvirus variola) remains a feared illness more than 25 years after its eradication. Historically, case-fatality rates (CFRs) varied between outbreaks (<1 to approximately 40 %), the reasons for which are incompletely understood. The extracellular enveloped virus (EEV) form of orthopoxvirus progeny is hypothesized to disseminate infection. Investigations with the closely related Orthopoxvirus vaccinia have associated increased comet formation (EEV production) with increased mouse mortality (pathogenicity). Other vaccinia virus genetic manipulations which affect EEV production inconsistently support this association. However, antisera against vaccinia virus envelope protect mice from lethal challenge, further supporting a critical role for EEV in pathogenicity. Here, we show that the increased comet formation phenotypes of a diverse collection of variola viruses associate with strain phylogeny and geographical origin, but not with increased outbreak-related CFRs; within clades, there may be an association of plaque size with CFR. The mechanisms for variola virus pathogenicity probably involves multiple host and pathogen factors.

Cell Source and Mechanism of Hair Cell Regeneration in the Neonatal Mouse Cochlea

DTIC Science & Technology

2015-09-30

indicating that the neonatal mouse cochlea can, to a limited ex tent. pro liferate in response to HC loss and th at some of these RESEARCH ARTICLE Atoh1...cations for other tetracycline-inducible mouse models used in inner ear research . Our studies also highlight potential problems with long term expression... studies for the 10% HC death model are underway. Further research is in progress to obtain a tamoxifen induction paradigm that will target 25% ofHCs

Transcriptomic Analysis of Lung Tissue from Cigarette Smoke-Induced Emphysema Murine Models and Human Chronic Obstructive Pulmonary Disease Show Shared and Distinct Pathways.

PubMed

Yun, Jeong H; Morrow, Jarrett; Owen, Caroline A; Qiu, Weiliang; Glass, Kimberly; Lao, Taotao; Jiang, Zhiqiang; Perrella, Mark A; Silverman, Edwin K; Zhou, Xiaobo; Hersh, Craig P

2017-07-01

Although cigarette smoke (CS) is the primary risk factor for chronic obstructive pulmonary disease (COPD), the underlying molecular mechanisms for the significant variability in developing COPD in response to CS are incompletely understood. We performed lung gene expression profiling of two different wild-type murine strains (C57BL/6 and NZW/LacJ) and two genetic models with mutations in COPD genome-wide association study genes (HHIP and FAM13A) after 6 months of chronic CS exposure and compared the results to human COPD lung tissues. We identified gene expression patterns that correlate with severity of emphysema in murine and human lungs. Xenobiotic metabolism and nuclear erythroid 2-related factor 2-mediated oxidative stress response were commonly regulated molecular response patterns in C57BL/6, Hhip +/- , and Fam13a -/- murine strains exposed chronically to CS. The CS-resistant Fam13a -/- mouse and NZW/LacJ strain revealed gene expression response pattern differences. The Fam13a -/- strain diverged in gene expression compared with C57BL/6 control only after CS exposure. However, the NZW/LacJ strain had a unique baseline expression pattern, enriched for nuclear erythroid 2-related factor 2-mediated oxidative stress response and xenobiotic metabolism, and converged to a gene expression pattern similar to the more susceptible wild-type C57BL/6 after CS exposure. These results suggest that distinct molecular pathways may account for resistance to emphysema. Surprisingly, there were few genes commonly modulated in mice and humans. Our study suggests that gene expression responses to CS may be largely species and model dependent, yet shared pathways could provide biologically significant insights underlying individual susceptibility to CS.

Myocardial dysfunction occurs prior to changes in ventricular geometry in mice with chronic kidney disease (CKD).

PubMed

Winterberg, Pamela D; Jiang, Rong; Maxwell, Josh T; Wang, Bo; Wagner, Mary B

2016-03-01

Uremic cardiomyopathy is responsible for high morbidity and mortality rates among patients with chronic kidney disease (CKD), but the underlying mechanisms contributing to this complex phenotype are incompletely understood. Myocardial deformation analyses (ventricular strain) of patients with mild CKD have recently been reported to predict adverse clinical outcome. We aimed to determine if early myocardial dysfunction in a mouse model of CKD could be detected using ventricular strain analyses. CKD was induced in 5-week-old male 129X1/SvJ mice through partial nephrectomy (5/6Nx) with age-matched mice undergoing bilateral sham surgeries serving as controls. Serial transthoracic echocardiography was performed over 16 weeks following induction of CKD. Invasive hemodynamic measurements were performed at 8 weeks. Gene expression and histology was performed on hearts at 8 and 16 weeks. CKD mice developed decreased longitudinal strain (-25 ± 4.2% vs. -29 ± 2.3%; P = 0.01) and diastolic dysfunction (E/A ratio 1.2 ± 0.15 vs. 1.9 ± 0.18; P < 0.001) compared to controls as early as 2 weeks following 5/6Nx. In contrast, ventricular hypertrophy was not apparent until 4 weeks. Hearts from CKD mice developed progressive fibrosis at 8 and 16 weeks with gene signatures suggestive of evolving heart failure with elevated expression of natriuretic peptides. Uremic cardiomyopathy in this model is characterized by early myocardial dysfunction which preceded observable changes in ventricular geometry. The model ultimately resulted in myocardial fibrosis and increased expression of natriuretic peptides suggestive of progressive heart failure. © 2016 The Authors. Physiological Reports published by Wiley Periodicals, Inc. on behalf of the American Physiological Society and The Physiological Society.

Cloned ferrets produced by somatic cell nuclear transfer

PubMed Central

Li, Ziyi; Sun, Xingshen; Chen, Juan; Liu, Xiaoming; Wisely, Samantha M.; Zhou, Qi; Renard, Jean-Paul; Leno, Gregory H.; Engelhardt, John F.

2007-01-01

Somatic cell nuclear transfer (SCNT) offers great potential for developing better animal models of human disease. The domestic ferret (Mustela putorius furo) is an ideal animal model for influenza infections and potentially other human respiratory diseases such as cystic fibrosis, where mouse models have failed to reproduce the human disease phenotype. Here, we report the successful production of live cloned, reproductively competent, ferrets using species-specific SCNT methodologies. Critical to developing a successful SCNT protocol for the ferret was the finding that hormonal treatment, normally used for superovulation, adversely affected the developmental potential of recipient oocytes. The onset of Oct4 expression was delayed and incomplete in parthenogenetically activated oocytes collected from hormone-treated females relative to oocytes collected from females naturally mated with vasectomized males. Stimulation induced by mating and in vitro oocyte maturation produced the optimal oocyte recipient for SCNT. Although nuclear injection and cell fusion produced mid-term fetuses at equivalent rates (~3–4%), only cell fusion gave rise to healthy surviving clones. Single cell fusion rates and the efficiency of SCNT were also enhanced by placing two somatic cells into the perivitelline space. These species-specific modifications facilitated the birth of live, healthy, and fertile cloned ferrets. The development of microsatellite genotyping for domestic ferrets confirmed that ferret clones were genetically derived from their respective somatic cells and unrelated to their surrogate mother. With this technology, it is now feasible to begin generating genetically defined ferrets for studying transmissible and inherited human lung diseases. Cloning of the domestic ferret may also aid in recovery and conservation of the endangered black-footed ferret and European mink. PMID:16584722

Analyses of cell surface molecules on hepatic stem/progenitor cells in mouse fetal liver.

PubMed

Kakinuma, Sei; Ohta, Haruhiko; Kamiya, Akihide; Yamazaki, Yuji; Oikawa, Tsunekazu; Okada, Ken; Nakauchi, Hiromitsu

2009-07-01

Hepatic stem/progenitor cells possess active proliferative ability and the capacity for differentiation into hepatic and cholangiocytic lineages. Our group and others have shown that a prospectively defined population in mid-gestational fetal liver contains hepatic stem/progenitor cells. However, the phenotypes of such cells are incompletely elucidated. We analyzed the profile of cell-surface molecules on primary hepatic stem/progenitor cells. Expression of cell surface molecules on primary hepatic stem/progenitor cells in mouse mid-gestational fetal liver was analyzed using flow cytometric multicolor analyses and colony-formation assays. The potential of the cells for liver repopulation was examined by transplantation assay. We found that CD13 (aminopeptidase N) was detected on the cells of the previously reported (Dlk/Pref-1(+)) hepatic stem/progenitor fraction. Colony-formation assays revealed that the CD13(+) fraction, compared with the Dlk(+) fraction, of non-hematopoietic cells in fetal liver was enriched in hepatic stem/progenitor cells. Transplantation assay showed the former fraction exhibited repopulating potential in regenerating liver. Moreover, flow cytometric analysis for over 90 antigens demonstrated enrichment of hepatic stem/progenitor cells using several positive selection markers, including (hitherto unknown) CD13, CD73, CD106, and CD133. Our data indicated that CD13 is a positive selection marker for hepatic stem/progenitor cells in mid-gestational fetal liver.

Macrophage activation by heparanase is mediated by TLR-2 and TLR-4 and associates with plaque progression.

PubMed

Blich, Miry; Golan, Amnon; Arvatz, Gil; Sebbag, Anat; Shafat, Itay; Sabo, Edmond; Cohen-Kaplan, Victoria; Petcherski, Sirouch; Avniel-Polak, Shani; Eitan, Amnon; Hammerman, Haim; Aronson, Doron; Axelman, Elena; Ilan, Neta; Nussbaum, Gabriel; Vlodavsky, Israel

2013-02-01

Factors and mechanisms that activate macrophages in atherosclerotic plaques are incompletely understood. We examined the capacity of heparanase to activate macrophages. Highly purified heparanase was added to mouse peritoneal macrophages and macrophage-like J774 cells, and the levels of tumor necrosis factor-α, matrix metalloproteinase-9, interlukin-1, and monocyte chemotactic protein-1 were evaluated by ELISA. Gene expression was determined by RT-PCR. Cells collected from Toll-like receptor-2 and Toll-like receptor-4 knockout mice were evaluated similarly. Heparanase levels in the plasma of patients with acute myocardial infarction, stable angina, and healthy subjects were determined by ELISA. Immunohistochemistry was applied to detect the expression of heparanase in control specimens and specimens of patients with stable angina or acute myocardial infarction. Addition or overexpression of heparanase variants resulted in marked increase in tumor necrosis factor-α, matrix metalloproteinase-9, interlukin-1, and monocyte chemotactic protein-1 levels. Mouse peritoneal macrophages harvested from Toll-like receptor-2 or Toll-like receptor-4 knockout mice were not activated by heparanase. Plasma heparanase level was higher in patients with acute myocardial infarction, compared with patients with stable angina and healthy subjects. Pathologic coronary specimens obtained from vulnerable plaques showed increased heparanase staining compared with specimens of stable plaque and controls. Heparanase activates macrophages, resulting in marked induction of cytokine expression associated with plaque progression toward vulnerability.

Complete TCRα gene locus control region activity in T cells derived in vitro from embryonic stem cells

PubMed Central

Lahiji, Armin; Kučerová-Levisohn, Martina; Lovett, Jordana; Holmes, Roxanne; Zúñiga-Pflücker, Juan Carlos; Ortiz, Benjamin D.

2013-01-01

Locus Control Regions (LCR) are cis-acting gene regulatory elements with the unique, integration site-independent ability to transfer the characteristics of their locus-of-origin’s gene expression pattern to a linked transgene in mice. LCR activities have been discovered in numerous T cell lineage expressed gene loci. These elements can be adapted to the design of stem cell gene therapy vectors that direct robust therapeutic gene expression to the T cell progeny of engineered stem cells. Currently, transgenic mice provide the only experimental approach that wholly supports all the critical aspects of LCR activity. Herein we report manifestation of all key features of mouse T cell receptor (TCR)-α gene LCR function in T cells derived in vitro from mouse embryonic stem cells (ESC). High level, copy number-related TCRα LCR-linked reporter gene expression levels are cell type-restricted in this system, and upregulated during the expected stage transition of T cell development. We further report that de novo introduction of TCRα LCR linked transgenes into existing T cell lines yields incomplete LCR activity. Together, these data indicate that establishing full TCRα LCR activity requires critical molecular events occurring prior to final T-lineage determination. This study additionally validates a novel, tractable and more rapid approach for the study of LCR activity in T cells, and its translation to therapeutic genetic engineering. PMID:23720809

The triple monoamine re-uptake inhibitor DOV 216,303 promotes functional recovery after spinal cord contusion injury in mice.

PubMed

Chu, Tak-Ho; Cummins, Karen; Stys, Peter K

2018-05-14

Serotonin, noradrenaline and dopamine are important neuromodulators for locomotion in the spinal cord. Disruption of descending axons after spinal cord injury resulted in reduction of excitatory and neuromodulatory inputs to spinal neurons for locomotion. Receptor agonists or reuptake inhibitors for these neuromodulators have been shown to be beneficial in incomplete spinal cord injury. In this study, we tested a triple re-uptake inhibitor, DOV 216,303, for its ability to affect motor function recovery after spinal cord injury in mice. We impacted C57 mouse spinal cord at the T11 vertebral level and administered vehicle or DOV 216,303 at 10 mg/kg, b.i.d via intraperitoneal injections for 7 days. We monitored motor function with the Basso Mouse Scale for locomotion for 4 weeks. Spinal cords were harvested and histological examinations were performed to assess tissue sparing and lesion severity. Results showed that DOV 216,303-treated mice recovered significantly better than vehicle treated mice starting at 14 days post injury until the end of the survival period. Lesion size of the DOV 216,303 treated mice was also smaller compared to that of vehicle treated mice. This study suggests DOV 216,303 as a potential therapeutic after spinal cord injury warrants further investigation. Copyright © 2018 Elsevier B.V. All rights reserved.

Therapeutic Targeting of the IL-6 Trans-Signaling/Mechanistic Target of Rapamycin Complex 1 Axis in Pulmonary Emphysema.

PubMed

Ruwanpura, Saleela M; McLeod, Louise; Dousha, Lovisa F; Seow, Huei J; Alhayyani, Sultan; Tate, Michelle D; Deswaerte, Virginie; Brooks, Gavin D; Bozinovski, Steven; MacDonald, Martin; Garbers, Christoph; King, Paul T; Bardin, Philip G; Vlahos, Ross; Rose-John, Stefan; Anderson, Gary P; Jenkins, Brendan J

2016-12-15

The potent immunomodulatory cytokine IL-6 is consistently up-regulated in human lungs with emphysema and in mouse emphysema models; however, the mechanisms by which IL-6 promotes emphysema remain obscure. IL-6 signals using two distinct modes: classical signaling via its membrane-bound IL-6 receptor (IL-6R), and trans-signaling via a naturally occurring soluble IL-6R. To identify whether IL-6 trans-signaling and/or classical signaling contribute to the pathogenesis of emphysema. We used the gp130 F/F genetic mouse model for spontaneous emphysema and cigarette smoke-induced emphysema models. Emphysema in mice was quantified by various methods including in vivo lung function and stereology, and terminal deoxynucleotidyl transferase dUTP nick end labeling assay was used to assess alveolar cell apoptosis. In mouse and human lung tissues, the expression level and location of IL-6 signaling-related genes and proteins were measured, and the levels of IL-6 and related proteins in sera from emphysematous mice and patients were also assessed. Lung tissues from patients with emphysema, and from spontaneous and cigarette smoke-induced emphysema mouse models, were characterized by excessive production of soluble IL-6R. Genetic blockade of IL-6 trans-signaling in emphysema mouse models and therapy with the IL-6 trans-signaling antagonist sgp130Fc ameliorated emphysema by suppressing augmented alveolar type II cell apoptosis. Furthermore, IL-6 trans-signaling-driven emphysematous changes in the lung correlated with mechanistic target of rapamycin complex 1 hyperactivation, and treatment of emphysema mouse models with the mechanistic target of rapamycin complex 1 inhibitor rapamycin attenuated emphysematous changes. Collectively, our data reveal that specific targeting of IL-6 trans-signaling may represent a novel treatment strategy for emphysema.

A comparative evaluation of the tissue responses associated with polymeric implants in the rat and mouse.

PubMed

Kidd, Kameha R; Dal Ponte, Donny B; Kellar, Robert S; Williams, Stuart K

2002-03-15

End product application is an important consideration when evaluating a material in an in vivo setting (Didisheim, Cardiovasc Pathol 1993;2:1S-2S). Small animal models allow high through-put evaluation of biocompatability. Previous preclinical evaluations have often used a rat subcutaneous model for the characterization of material-tissue interaction. Recent advances in genetic manipulation have provided mouse models with selective expression of a wide range of critical proteins. The rat model does not have many of the resources (i.e., knockouts, SCID, nude) that are present in mouse strains. The availability of these mice provides a resource to delineate the mechanisms regulating the healing associated with implants. However, before the mouse models can be used, they must be validated with respect to their ability to accurately assess tissue responses to materials. In this study the tissue responses after the implantation of expanded polytetrafluoroethylene (ePTFE) were compared between rat and mouse. Discs of ePTFE (30-microm internodal distance) were implanted in subcutaneous and epididymal fat tissue of rats (Sprague-Dawley) and mice (129-SVJ). After 5 weeks the samples were removed and evaluated for vascular density, inflammation, and fibrous encapsulation. No difference in the vessel density was observed within the peri-implant subcutaneous and adipose tissue or within the porous material. However, a significant difference was found in the number of activated macrophages and giant cells between these two species. Implants in the rat exhibited greater numbers of activated inflammatory cells in the peri-implant tissue. The data indicate that the mouse and rat provide a comparable model for evaluating angiogenesis and neovascularization associated with synthetic porous implants. Copyright 2001 John Wiley & Sons, Inc. J Biomed Mater Res 59: 682-689, 2002

Touchscreen learning deficits in Ube3a, Ts65Dn and Mecp2 mouse models of neurodevelopmental disorders with intellectual disabilities.

PubMed

Leach, P T; Crawley, J N

2017-12-20

Mutant mouse models of neurodevelopmental disorders with intellectual disabilities provide useful translational research tools, especially in cases where robust cognitive deficits are reproducibly detected. However, motor, sensory and/or health issues consequent to the mutation may introduce artifacts that preclude testing in some standard cognitive assays. Touchscreen learning and memory tasks in small operant chambers have the potential to circumvent these confounds. Here we use touchscreen visual discrimination learning to evaluate performance in the maternally derived Ube3a mouse model of Angelman syndrome, the Ts65Dn trisomy mouse model of Down syndrome, and the Mecp2 Bird mouse model of Rett syndrome. Significant deficits in acquisition of a 2-choice visual discrimination task were detected in both Ube3a and Ts65Dn mice. Procedural control measures showed no genotype differences during pretraining phases or during acquisition. Mecp2 males did not survive long enough for touchscreen training, consistent with previous reports. Most Mecp2 females failed on pretraining criteria. Significant impairments on Morris water maze spatial learning were detected in both Ube3a and Ts65Dn, replicating previous findings. Abnormalities on rotarod in Ube3a, and on open field in Ts65Dn, replicating previous findings, may have contributed to the observed acquisition deficits and swim speed abnormalities during water maze performance. In contrast, these motor phenotypes do not appear to have affected touchscreen procedural abilities during pretraining or visual discrimination training. Our findings of slower touchscreen learning in 2 mouse models of neurodevelopmental disorders with intellectual disabilities indicate that operant tasks offer promising outcome measures for the preclinical discovery of effective pharmacological therapeutics. © 2017 John Wiley & Sons Ltd and International Behavioural and Neural Genetics Society.

Voltage-dependent ion channels in the mouse RPE: comparison with Norrie disease mice.

PubMed

Wollmann, Guido; Lenzner, Steffen; Berger, Wolfgang; Rosenthal, Rita; Karl, Mike O; Strauss, Olaf

2006-03-01

We studied electrophysiological properties of cultured retinal pigment epithelial (RPE) cells from mouse and a mouse model for Norrie disease. Wild-type RPE cells revealed the expression of ion channels known from other species: delayed-rectifier K(+) channels composed of Kv1.3 subunits, inward rectifier K(+) channels, Ca(V)1.3 L-type Ca(2+) channels and outwardly rectifying Cl(-) channels. Expression pattern and the ion channel characteristics current density, blocker sensitivity, kinetics and voltage-dependence were compared in cells from wild-type and Norrie mice. Although no significant differences were observed, our study provides a base for future studies on ion channel function and dysfunction in transgenic mouse models.

Riluzole does not improve lifespan or motor function in three ALS mouse models.

PubMed

Hogg, Marion C; Halang, Luise; Woods, Ina; Coughlan, Karen S; Prehn, Jochen H M

2018-08-01

Riluzole is the most widespread therapeutic for treatment of the progressive degenerative disease amyotrophic lateral sclerosis (ALS). Riluzole gained FDA approval in 1995 before the development of ALS mouse models. We assessed riluzole in three transgenic ALS mouse models: the SOD1 G93A model, the TDP-43 A315T model, and the recently developed FUS (1-359) model. Age, sex and litter-matched mice were treated with riluzole (22 mg/kg) in drinking water or vehicle (DMSO) from symptom onset. Lifespan was assessed and motor function tests were carried out twice weekly to determine whether riluzole slowed disease progression. Riluzole treatment had no significant benefit on lifespan in any of the ALS mouse models tested. Riluzole had no significant impact on decline in motor performance in the FUS (1-359) and SOD1 G93A transgenic mice as assessed by Rotarod and stride length analysis. Riluzole is widely prescribed for ALS patients despite questions surrounding its efficacy. Our data suggest that if riluzole was identified as a therapeutic candidate today it would not progress past pre-clinical assessment. This raises questions about the standards used in pre-clinical assessment of therapeutic candidates for the treatment of ALS.

Mouse-based genetic modeling and analysis of Down syndrome

PubMed Central

Xing, Zhuo; Li, Yichen; Pao, Annie; Bennett, Abigail S.; Tycko, Benjamin; Mobley, William C.; Yu, Y. Eugene

2016-01-01

Introduction Down syndrome (DS), caused by human trisomy 21 (Ts21), can be considered as a prototypical model for understanding the effects of chromosomal aneuploidies in other diseases. Human chromosome 21 (Hsa21) is syntenically conserved with three regions in the mouse genome. Sources of data A review of recent advances in genetic modeling and analysis of DS. Using Cre/loxP-mediated chromosome engineering, a substantial number of new mouse models of DS have recently been generated, which facilitates better understanding of disease mechanisms in DS. Areas of agreement Based on evolutionary conservation, Ts21 can be modeled by engineered triplication of Hsa21 syntenic regions in mice. The validity of the models is supported by the exhibition of DS-related phenotypes. Areas of controversy Although substantial progress has been made, it remains a challenge to unravel the relative importance of specific candidate genes and molecular mechanisms underlying the various clinical phenotypes. Growing points Further understanding of mechanisms based on data from mouse models, in parallel with human studies, may lead to novel therapies for clinical manifestations of Ts21 and insights to the roles of aneuploidies in other developmental disorders and cancers. PMID:27789459

Humanized NOG mice as a model for tuberculosis vaccine-induced immunity: a comparative analysis with the mouse and guinea pig models of tuberculosis.

PubMed

Grover, Ajay; Troy, Amber; Rowe, Jenny; Troudt, JoLynn M; Creissen, Elizabeth; McLean, Jennifer; Banerjee, Prabal; Feuer, Gerold; Izzo, Angelo A

2017-09-01

The humanized mouse model has been developed as a model to identify and characterize human immune responses to human pathogens and has been used to better identify vaccine candidates. In the current studies, the humanized mouse was used to determine the ability of a vaccine to affect the immune response to infection with Mycobacterium tuberculosis. Both human CD4 + and CD8 + T cells responded to infection in humanized mice as a result of infection. In humanized mice vaccinated with either BCG or with CpG-C, a liposome-based formulation containing the M. tuberculosis antigen ESAT-6, both CD4 and CD8 T cells secreted cytokines that are known to be required for induction of protective immunity. In comparison to the C57BL/6 mouse model and Hartley guinea pig model of tuberculosis, data obtained from humanized mice complemented the data observed in the former models and provided further evidence that a vaccine can induce a human T-cell response. Humanized mice provide a crucial pre-clinical platform for evaluating human T-cell immune responses in vaccine development against M. tuberculosis. © 2017 John Wiley & Sons Ltd.

The Use of the Interconnected Model of Teacher Professional Growth for Understanding the Development of Science Teachers' Knowledge on Models and Modelling

ERIC Educational Resources Information Center

Justi, Rosaria; van Driel, Jan

2006-01-01

Models play an important role in science education. However, previous research has revealed that science teachers' content knowledge, curricular knowledge, and pedagogical content knowledge on models and modelling are often incomplete or inadequate. From this perspective, a research project was designed which aimed at the development of beginning…

Correcting Model Fit Criteria for Small Sample Latent Growth Models with Incomplete Data

ERIC Educational Resources Information Center

McNeish, Daniel; Harring, Jeffrey R.

2017-01-01

To date, small sample problems with latent growth models (LGMs) have not received the amount of attention in the literature as related mixed-effect models (MEMs). Although many models can be interchangeably framed as a LGM or a MEM, LGMs uniquely provide criteria to assess global data-model fit. However, previous studies have demonstrated poor…

Insights from zebrafish and mouse models on the activity and safety of ar-turmerone as a potential drug candidate for the treatment of epilepsy.

PubMed

Orellana-Paucar, Adriana Monserrath; Afrikanova, Tatiana; Thomas, Joice; Aibuldinov, Yelaman K; Dehaen, Wim; de Witte, Peter A M; Esguerra, Camila V

2013-01-01

In a previous study, we uncovered the anticonvulsant properties of turmeric oil and its sesquiterpenoids (ar-turmerone, α-, β-turmerone and α-atlantone) in both zebrafish and mouse models of chemically-induced seizures using pentylenetetrazole (PTZ). In this follow-up study, we aimed at evaluating the anticonvulsant activity of ar-turmerone further. A more in-depth anticonvulsant evaluation of ar-turmerone was therefore carried out in the i.v. PTZ and 6-Hz mouse models. The potential toxic effects of ar-turmerone were evaluated using the beam walking test to assess mouse motor function and balance. In addition, determination of the concentration-time profile of ar-turmerone was carried out for a more extended evaluation of its bioavailability in the mouse brain. Ar-turmerone displayed anticonvulsant properties in both acute seizure models in mice and modulated the expression patterns of two seizure-related genes (c-fos and brain-derived neurotrophic factor [bdnf]) in zebrafish. Importantly, no effects on motor function and balance were observed in mice after treatment with ar-turmerone even after administering a dose 500-fold higher than the effective dose in the 6-Hz model. In addition, quantification of its concentration in mouse brains revealed rapid absorption after i.p. administration, capacity to cross the BBB and long-term brain residence. Hence, our results provide additional information on the anticonvulsant properties of ar-turmerone and support further evaluation towards elucidating its mechanism of action, bioavailability, toxicity and potential clinical application.

Insights from Zebrafish and Mouse Models on the Activity and Safety of Ar-Turmerone as a Potential Drug Candidate for the Treatment of Epilepsy

PubMed Central

Orellana-Paucar, Adriana Monserrath; Afrikanova, Tatiana; Thomas, Joice; Aibuldinov, Yelaman K.; Dehaen, Wim; de Witte, Peter A. M.; Esguerra, Camila V.

2013-01-01

In a previous study, we uncovered the anticonvulsant properties of turmeric oil and its sesquiterpenoids (ar-turmerone, α-, β-turmerone and α-atlantone) in both zebrafish and mouse models of chemically-induced seizures using pentylenetetrazole (PTZ). In this follow-up study, we aimed at evaluating the anticonvulsant activity of ar-turmerone further. A more in-depth anticonvulsant evaluation of ar-turmerone was therefore carried out in the i.v. PTZ and 6-Hz mouse models. The potential toxic effects of ar-turmerone were evaluated using the beam walking test to assess mouse motor function and balance. In addition, determination of the concentration-time profile of ar-turmerone was carried out for a more extended evaluation of its bioavailability in the mouse brain. Ar-turmerone displayed anticonvulsant properties in both acute seizure models in mice and modulated the expression patterns of two seizure-related genes (c-fos and brain-derived neurotrophic factor [bdnf]) in zebrafish. Importantly, no effects on motor function and balance were observed in mice after treatment with ar-turmerone even after administering a dose 500-fold higher than the effective dose in the 6-Hz model. In addition, quantification of its concentration in mouse brains revealed rapid absorption after i.p. administration, capacity to cross the BBB and long-term brain residence. Hence, our results provide additional information on the anticonvulsant properties of ar-turmerone and support further evaluation towards elucidating its mechanism of action, bioavailability, toxicity and potential clinical application. PMID:24349101

Longitudinal Multiplexed Measurement of Quantitative Proteomic Signatures in Mouse Lymphoma Models Using Magneto-Nanosensors

PubMed Central

Lee, Jung-Rok; Appelmann, Iris; Miething, Cornelius; Shultz, Tyler O.; Ruderman, Daniel; Kim, Dokyoon; Mallick, Parag; Lowe, Scott W.; Wang, Shan X.

2018-01-01

Cancer proteomics is the manifestation of relevant biological processes in cancer development. Thus, it reflects the activities of tumor cells, host-tumor interactions, and systemic responses to cancer therapy. To understand the causal effects of tumorigenesis or therapeutic intervention, longitudinal studies are greatly needed. However, most of the conventional mouse experiments are unlikely to accommodate frequent collection of serum samples with a large enough volume for multiple protein assays towards single-object analysis. Here, we present a technique based on magneto-nanosensors to longitudinally monitor the protein profiles in individual mice of lymphoma models using a small volume of a sample for multiplex assays. Methods: Drug-sensitive and -resistant cancer cell lines were used to develop the mouse models that render different outcomes upon the drug treatment. Two groups of mice were inoculated with each cell line, and treated with either cyclophosphamide or vehicle solution. Serum samples taken longitudinally from each mouse in the groups were measured with 6-plex magneto-nanosensor cytokine assays. To find the origin of IL-6, experiments were performed using IL-6 knock-out mice. Results: The differences in serum IL-6 and GCSF levels between the drug-treated and untreated groups were revealed by the magneto-nanosensor measurement on individual mice. Using the multiplex assays and mouse models, we found that IL-6 is secreted by the host in the presence of tumor cells upon the drug treatment. Conclusion: The multiplex magneto-nanosensor assays enable longitudinal proteomic studies on mouse tumor models to understand tumor development and therapy mechanisms more precisely within a single biological object. PMID:29507628

Longitudinal Multiplexed Measurement of Quantitative Proteomic Signatures in Mouse Lymphoma Models Using Magneto-Nanosensors.

PubMed

Lee, Jung-Rok; Appelmann, Iris; Miething, Cornelius; Shultz, Tyler O; Ruderman, Daniel; Kim, Dokyoon; Mallick, Parag; Lowe, Scott W; Wang, Shan X

2018-01-01

Cancer proteomics is the manifestation of relevant biological processes in cancer development. Thus, it reflects the activities of tumor cells, host-tumor interactions, and systemic responses to cancer therapy. To understand the causal effects of tumorigenesis or therapeutic intervention, longitudinal studies are greatly needed. However, most of the conventional mouse experiments are unlikely to accommodate frequent collection of serum samples with a large enough volume for multiple protein assays towards single-object analysis. Here, we present a technique based on magneto-nanosensors to longitudinally monitor the protein profiles in individual mice of lymphoma models using a small volume of a sample for multiplex assays. Methods: Drug-sensitive and -resistant cancer cell lines were used to develop the mouse models that render different outcomes upon the drug treatment. Two groups of mice were inoculated with each cell line, and treated with either cyclophosphamide or vehicle solution. Serum samples taken longitudinally from each mouse in the groups were measured with 6-plex magneto-nanosensor cytokine assays. To find the origin of IL-6, experiments were performed using IL-6 knock-out mice. Results: The differences in serum IL-6 and GCSF levels between the drug-treated and untreated groups were revealed by the magneto-nanosensor measurement on individual mice. Using the multiplex assays and mouse models, we found that IL-6 is secreted by the host in the presence of tumor cells upon the drug treatment. Conclusion: The multiplex magneto-nanosensor assays enable longitudinal proteomic studies on mouse tumor models to understand tumor development and therapy mechanisms more precisely within a single biological object.

"Mouse Clone Model" for evaluating the immunogenicity and tumorigenicity of pluripotent stem cells.

PubMed

Zhang, Gang; Zhang, Yi

2015-12-18

To investigate the immune-rejection and tumor-formation potentials of induced pluripotent stem cells and other stem cells, we devised a model-designated the "Mouse Clone Model"-which combined the theory of somatic animal cloning, tetraploid complementation, and induced pluripotent stem cells to demonstrate the applicability of stem cells for transplantation therapy.

Investigating Mechanisms of Chronic Kidney Disease in Mouse Models

PubMed Central

Eddy, Allison A.; Okamura, Daryl M.; Yamaguchi, Ikuyo; López-Guisa, Jesús M.

2011-01-01

Animal models of chronic kidney disease (CKD) are important experimental tools that are used to investigate novel mechanistic pathways and to validate potential new therapeutic interventions prior to pre-clinical testing in humans. Over the past several years, mouse CKD models have been extensively used for these purposes. Despite significant limitations, the model of unilateral ureteral obstruction (UUO) has essentially become the high throughput in vivo model, as it recapitulates the fundamental pathogenetic mechanisms that typify all forms of CKD in a relatively short time span. In addition, several alternative mouse models are available that can be used to validate new mechanistic paradigms and/or novel therapies. Several models are reviewed – both genetic and experimentally induced – that provide investigators with an opportunity to include renal functional study end-points together with quantitative measures of fibrosis severity, something that is not possible with the UUO model. PMID:21695449

CHARACTERIZATION OF AEROMONAS VIRULENCE USING AN IMMUNOCOMPROMISED MOUSE MODEL

EPA Science Inventory

An immunocompromised mouse model was used to characterize Aeromonas strains for their ability to cause opportunistic, extraintestinal infections. A total of 34 isolates of Aeromonas (A. hydrophila [n = 12]), A. veronii biotype sobria [n = 7], A. caviae [n = 4], A. enchelia [n = 4...

Systematic comparison of the behaviors produced by computational models of epileptic neocortex.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Warlaumont, A. S.; Lee, H. C.; Benayoun, M.

2010-12-01

Two existing models of brain dynamics in epilepsy, one detailed (i.e., realistic) and one abstract (i.e., simplified) are compared in terms of behavioral range and match to in vitro mouse recordings. A new method is introduced for comparing across computational models that may have very different forms. First, high-level metrics were extracted from model and in vitro output time series. A principal components analysis was then performed over these metrics to obtain a reduced set of derived features. These features define a low-dimensional behavior space in which quantitative measures of behavioral range and degree of match to real data canmore » be obtained. The detailed and abstract models and the mouse recordings overlapped considerably in behavior space. Both the range of behaviors and similarity to mouse data were similar between the detailed and abstract models. When no high-level metrics were used and principal components analysis was computed over raw time series, the models overlapped minimally with the mouse recordings. The method introduced here is suitable for comparing across different kinds of model data and across real brain recordings. It appears that, despite differences in form and computational expense, detailed and abstract models do not necessarily differ in their behaviors.« less

Genetics of SLE: evidence from mouse models.

PubMed

Morel, Laurence

2010-06-01

Great progress has been made in the field of lupus genetics in the past few years, notably with the publication of genome-wide association studies in humans and the identification of susceptibility genes (including Fcgr2b, Ly108, Kallikrein genes and Coronin-1A) in mouse models of spontaneous lupus. This influx of new information has revealed an ever-increasing interdependence between the mouse and human systems for unraveling the genetic basis of lupus susceptibility. Studies in the 1980s and 1990s established that mice prone to spontaneous lupus constitute excellent models of the genetic architecture of human systemic lupus erythematosus (SLE). This notion has been greatly strengthened by the convergence of the functional pathways that are defective in both human and murine lupus. Within these pathways, variants in a number of genes have now been shown to be directly associated with lupus in both species. Consequently, mouse models will continue to serve a pre-eminent role in lupus genetics research, with an increased emphasis on mechanistic and molecular studies of human susceptibility alleles.

The role of vertebrate models in understanding craniosynostosis.

PubMed

Holmes, Greg

2012-09-01

Craniosynostosis (CS), the premature fusion of cranial sutures, is a relatively common pediatric anomaly, occurring in isolation or as part of a syndrome. A growing number of genes with pathologic mutations have been identified for syndromic and nonsyndromic CS. The study of human sutural material obtained post-operatively is not sufficient to understand the etiology of CS, for which animal models are indispensable. The similarity of the human and murine calvarial structure, our knowledge of mouse genetics and biology, and ability to manipulate the mouse genome make the mouse the most valuable model organism for CS research. A variety of mouse mutants are available that model specific human CS mutations or have CS phenotypes. These allow characterization of the biochemical and morphological events, often embryonic, which precede suture fusion. Other vertebrate organisms have less functional genetic utility than mice, but the rat, rabbit, chick, zebrafish, and frog provide alternative systems in which to validate or contrast molecular functions relevant to CS.

Quantification of oxygen-induced retinopathy in the mouse: a model of vessel loss, vessel regrowth and pathological angiogenesis

PubMed Central

Connor, Kip M; Krah, Nathan M; Dennison, Roberta J; Aderman, Christopher M; Chen, Jing; Guerin, Karen I; Sapieha, Przemyslaw; Stahl, Andreas; Willett, Keirnan L; Smith, Lois E H

2013-01-01

The mouse model of oxygen-induced retinopathy (OIR) has been widely used in studies related to retinopathy of prematurity, proliferative diabetic retinopathy and in studies evaluating the efficacy of antiangiogenic compounds. In this model, 7-d-old (P7) mouse pups with nursing mothers are subjected to hyperoxia (75% oxygen) for 5 d, which inhibits retinal vessel growth and causes significant vessel loss. on P12, mice are returned to room air and the hypoxic avascular retina triggers both normal vessel regrowth and retinal neovascularization (NV), which is maximal at P17. neovascularization spontaneously regresses between P17 and P25. although the OIR model has been the cornerstone of studies investigating proliferative retinopathies, there is currently no harmonized protocol to assess aspects of angiogenesis and treatment outcome. In this protocol we describe standards for mouse size, sample size, retinal preparation, quantification of vascular loss, vascular regrowth, NV and neovascular regression. PMID:19816419

Biology and therapy of inherited retinal degenerative disease: insights from mouse models

PubMed Central

Veleri, Shobi; Lazar, Csilla H.; Chang, Bo; Sieving, Paul A.; Banin, Eyal; Swaroop, Anand

2015-01-01

Retinal neurodegeneration associated with the dysfunction or death of photoreceptors is a major cause of incurable vision loss. Tremendous progress has been made over the last two decades in discovering genes and genetic defects that lead to retinal diseases. The primary focus has now shifted to uncovering disease mechanisms and designing treatment strategies, especially inspired by the successful application of gene therapy in some forms of congenital blindness in humans. Both spontaneous and laboratory-generated mouse mutants have been valuable for providing fundamental insights into normal retinal development and for deciphering disease pathology. Here, we provide a review of mouse models of human retinal degeneration, with a primary focus on diseases affecting photoreceptor function. We also describe models associated with retinal pigment epithelium dysfunction or synaptic abnormalities. Furthermore, we highlight the crucial role of mouse models in elucidating retinal and photoreceptor biology in health and disease, and in the assessment of novel therapeutic modalities, including gene- and stem-cell-based therapies, for retinal degenerative diseases. PMID:25650393

A Progressive Translational Mouse Model of Human VCP Disease: The VCP R155H/+ Mouse

PubMed Central

Nalbandian, Angèle; Llewellyn, Katrina J.; Badadani, Mallikarjun; Yin, Hong Z.; Nguyen, Christopher; Katheria, Veeral; Watts, Giles; Mukherjee, Jogeshwar; Vesa, Jouni; Caiozzo, Vincent; Mozaffar, Tahseen; Weiss, John H.; Kimonis, Virginia E.

2012-01-01

Introduction Mutations in the valosin containing protein (VCP) gene cause hereditary Inclusion Body Myopathy (hIBM) associated with Paget disease of bone (PDB), and frontotemporal dementia (FTD). More recently they have been linked to 2% of familial ALS cases. A knock-in mouse model offers the opportunity to study VCP-associated pathogenesis. Methods The VCPR155H/+ knock-in mouse model was assessed for muscle strength, immunohistochemical, Western, apoptosis, autophagy and MicroPET/CT imaging analyses. Results VCPR155H/+ mice developed significant progressive muscle weakness, and the quadriceps and brain developed progressive cytoplasmic accumulation of TDP-43, ubiquitin-positive inclusion bodies and increased LC3-II staining. MicroCT analyses revealed Paget-like lesions at the ends of long bones. Spinal cord demonstrated neurodegenerative changes, ubiquitin, and TDP-43 pathology of motor neurons. Discussion VCPR155H/+ knock-in mice represent an excellent pre-clinical model for understanding VCP-associated disease mechanisms and future treatments. PMID:23169451

CaveCAD: a tool for architectural design in immersive virtual environments

NASA Astrophysics Data System (ADS)

Schulze, Jürgen P.; Hughes, Cathleen E.; Zhang, Lelin; Edelstein, Eve; Macagno, Eduardo

2014-02-01

Existing 3D modeling tools were designed to run on desktop computers with monitor, keyboard and mouse. To make 3D modeling possible with mouse and keyboard, many 3D interactions, such as point placement or translations of geometry, had to be mapped to the 2D parameter space of the mouse, possibly supported by mouse buttons or keyboard keys. We hypothesize that had the designers of these existing systems had been able to assume immersive virtual reality systems as their target platforms, they would have been able to design 3D interactions much more intuitively. In collaboration with professional architects, we created a simple, but complete 3D modeling tool for virtual environments from the ground up and use direct 3D interaction wherever possible and adequate. In this publication, we present our approaches for interactions for typical 3D modeling functions, such as geometry creation, modification of existing geometry, and assignment of surface materials. We also discuss preliminary user experiences with this system.

IN VIVO ANTI-INFLAMMATORY EFFECTS OF TARAXASTEROL AGAINST ANIMAL MODELS

PubMed Central

Wang, Ying; Li, Guan-Hao; Liu, Xin-Yu; Xu, Lu; Wang, Sha-Sha; Zhang, Xue-Mei

2017-01-01

Background: Traditional Chinese medicine Taraxacum officinale has been widely used to treat various inflammatory diseases. Taraxasterol is one of the main active components isolated from Taraxacum officinale. Recently, we have demonstrated that taraxasterol has the in vitro anti-inflammatory effects. This study aims to determine the in vivo anti-inflammatory effects of taraxasterol against animal models. Materials and Methods: Anti-inflammatory effects were assessed in four animal models by using dimethylbenzene-induced mouse ear edema, carrageenan-induced rat paw edema, acetic acid-induced mouse vascular permeability and cotton pellet-induced rat granuloma tests. Results: Our results demonstrated that taraxasterol dose-dependently attenuated dimethylbenzene-induced mouse ear edema and carrageenan-induced rat paw edema, decreased acetic acid-induced mouse vascular permeability and inhibited cotton pellet-induced rat granuloma formation. Conclusion: Our finding indicates that taraxasterol has obvious in vivo anti-inflammatory effects against animal models. It will provide experimental evidences for the traditional use of Taraxacum officinale and taraxasterol in inflammatory diseases. PMID:28480383

Prolonged diet induced obesity has minimal effects towards brain pathology in mouse model of cerebral amyloid angiopathy: implications for studying obesity-brain interactions in mice.

PubMed

Zhang, Le; Dasuri, Kalavathi; Fernandez-Kim, Sun-Ok; Bruce-Keller, Annadora J; Freeman, Linnea R; Pepping, Jennifer K; Beckett, Tina L; Murphy, M Paul; Keller, Jeffrey N

2013-09-01

Cerebral amyloid angiopathy (CAA) occurs in nearly every individual with Alzheimer's disease (AD) and Down's syndrome, and is the second largest cause of intracerebral hemorrhage. Mouse models of CAA have demonstrated evidence for increased gliosis contributing to CAA pathology. Nearly two thirds of Americans are overweight or obese, with little known about the effects of obesity on the brain, although increasingly the vasculature appears to be a principle target of obesity effects on the brain. In the current study we describe for the first time whether diet induced obesity (DIO) modulates glial reactivity, amyloid levels, and inflammatory signaling in a mouse model of CAA. In these studies we identify surprisingly that DIO does not significantly increase Aβ levels, astrocyte (GFAP) or microglial (IBA-1) gliosis in the CAA mice. However, within the hippocampal gyri a localized increase in reactive microglia were increased in the CA1 and stratum oriens relative to CAA mice on a control diet. DIO was observed to selectively increase IL-6 in CAA mice, with IL-1β and TNF-α not increased in CAA mice in response to DIO. Taken together, these data show that prolonged DIO has only modest effects towards Aβ in a mouse model of CAA, but appears to elevate some localized microglial reactivity within the hippocampal gyri and selective markers of inflammatory signaling. These data are consistent with the majority of the existing literature in other models of Aβ pathology, which surprisingly show a mixed profile of DIO effects towards pathological processes in mouse models of neurodegenerative disease. The importance for considering the potential impact of ceiling effects in pathology within mouse models of Aβ pathogenesis, and the current experimental limitations for DIO in mice to fully replicate metabolic dysfunction present in human obesity, are discussed. This article is part of a Special Issue entitled: Animal Models of Disease. Copyright © 2012. Published by Elsevier B.V.

Incomplete syllogisms as techniques of medicalization: The case of direct-to-consumer advertising in popular magazines, 1997 to 2003.

PubMed

Arney, Jennifer; Rafalovich, Adam

2007-01-01

The researchers collected a data set of consumer-directed print advertisements for antidepressant medications from three female-directed magazines, three male-directed magazines, and four common readership magazines published between 1997 and 2003. They evaluated these data for advertising techniques that enable drug advertisements to function as agents of medicalization. The investigators discuss the use of incomplete syllogisms in drug advertisements and identify strategies that might lead readers to frame personal physical and/or emotional conditions medically. Key features in advertisements function as the particular and general premises of a syllogism, and the concluding premise--that the reader has a mood disorder--is unarticulated but implied. The researchers examine the implications of incomplete syllogisms in advertisements and suggest that their use might lead readers to redefine their physical and/or emotional problems to fit medical models of mental distress.

3D numerical simulation of flow field with incompletely flaring gate pier in large unit discharge and deep tail water project

NASA Astrophysics Data System (ADS)

Zhao, Zhou; Junxing, Wang

2018-06-01

Limited by large unit discharge above the overflow weir and deep tail water inside the stilling basin, the incoming flow inside stilling basin is seriously short of enough energy dissipation and outgoing flow still carries much energy with large velocity, bound to result in secondary hydraulic jump outside stilling basin and scour downstream river bed. Based on the RNG k-ɛ turbulence model and the VOF method, this paper comparatively studies flow field between the conventional flat gate pier program and the incompletely flaring gate pier program to reveal energy dissipation mechanism of incomplete flaring gate pier. Results show that incompletely flaring gate pier can greatly promote the longitudinally stretched water jet to laterally diffuse and collide in the upstream region of stilling basin due to velocity gradients between adjacent inflow from each chamber through shrinking partial overflow flow chamber weir chamber, which would lead to large scale vertical axis vortex from the bottom to the surface and enhance mutual shear turbulence dissipation. This would significantly increase energy dissipation inside stilling basin to reduce outgoing velocity and totally solve the common hydraulic problems in large unit discharge and deep tail water projects.

Histological and reference system for the analysis of mouse intervertebral disc.

PubMed

Tam, Vivian; Chan, Wilson C W; Leung, Victor Y L; Cheah, Kathryn S E; Cheung, Kenneth M C; Sakai, Daisuke; McCann, Matthew R; Bedore, Jake; Séguin, Cheryle A; Chan, Danny

2018-01-01

A new scoring system based on histo-morphology of mouse intervertebral disc (IVD) was established to assess changes in different mouse models of IVD degeneration and repair. IVDs from mouse strains of different ages, transgenic mice, or models of artificially induced IVD degeneration were assessed. Morphological features consistently observed in normal, and early/later stages of degeneration were categorized into a scoring system focused on nucleus pulposus (NP) and annulus fibrosus (AF) changes. "Normal NP" exhibited a highly cellularized cell mass that decreased with natural ageing and in disc degeneration. "Normal AF" consisted of distinct concentric lamellar structures, which was disrupted in severe degeneration. NP/AF clefts indicated more severe changes. Consistent scores were obtained between experienced and new users. Altogether, our scoring system effectively differentiated IVD changes in various strains of wild-type and genetically modified mice and in induced models of IVD degeneration, and is applicable from the post-natal stage to the aged mouse. This scoring tool and reference resource addresses a pressing need in the field for studying IVD changes and cross-study comparisons in mice, and facilitates a means to normalize mouse IVD assessment between different laboratories. © 2017 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 36:233-243, 2018. © 2017 Orthopaedic Research Society. Published by Wiley Periodicals, Inc.

Generation of a mouse model for studying the role of upregulated RTEL1 activity in tumorigenesis.

PubMed

Wu, Xiaoli; Sandhu, Sumit; Nabi, Zinnatun; Ding, Hao

2012-10-01

Regulator of telomere length 1 (RTEL1) is a DNA helicase protein that has been demonstrated to be required for the maintenance of telomere length and genomic stability. It has also been found to be essential for DNA homologous recombination during DNA repairing. Human RTEL1 genomic locus (20q13.3) is frequently amplified in multiple types of human cancers, including hepatocellular carcinoma and gastrointestinal tract tumors, indicating that upregulated RTEL1 activity could be important for tumorigenesis. In this study, we have developed a conditional transgenic mouse model that overexpress mouse Rtel1 in a Cre-excision manner. By crossing with a ubiquitous Cre mouse line, we further demonstrated that these established Rtel1 conditional transgenic mice allow to efficiently and highly express a functional Rtel1 that is able to rescue the embryonic defects of Rtel1 null mouse allele. Furthermore, we demonstrated that more than 70% transgenic mice that widely overexpress Rtel1 developed liver tumors that recapitulate many malignant features of human hepatocellular carcinoma (HCC). Our work not only generated a valuable mouse model for determining the role of RTEL1 in the development of cancers, but also provided the first genetic evidence to support that amplification of RTEL1, as observed in several types of human cancers, is tumorigenic.

Promoting Endochondral Bone Repair Using Human Osteoarthritic Articular Chondrocytes.

PubMed

Bahney, Chelsea S; Jacobs, Linsey; Tamai, Robert; Hu, Diane; Luan, Tammy F; Wang, Miqi; Reddy, Sanjay; Park, Michelle; Limburg, Sonja; Kim, Hubert T; Marcucio, Ralph; Kuo, Alfred C

2016-03-01

Current tissue engineering strategies to heal critical-size bone defects through direct bone formation are limited by incomplete integration of grafts with host bone and incomplete graft vascularization. An alternative strategy for bone regeneration is the use of cartilage grafts that form bone through endochondral ossification. Endochondral cartilages stimulate angiogenesis and are remodeled into bone, but are found in very small quantities in growth plates and healing fractures. We sought to develop engineered endochondral cartilage grafts using osteoarthritic (OA) articular chondrocytes as a cell source. Such chondrocytes often undergo hypertrophy, which is a characteristic of endochondral cartilages. We compared the ability of unmodified human OA (hOA) cartilage and cartilage grafts formed in vitro from hOA chondrocytes to undergo endochondral ossification in mice. Scaffold-free engineered chondrocyte grafts were generated by pelleting chondrocytes, followed by culture with transforming growth factor-β1 (TGF-β1) and bone morphogenetic protein 4. Samples derived from either primary or passaged chondrocytes were implanted subcutaneously into immunocompromised mice. Grafts derived from passaged chondrocytes from three patients were implanted into critical-size tibial defects in mice. Bone formation was assessed with histology after 4 weeks of implantation. The composition of tibial repair tissue was quantified with histomorphometry. Engineered cartilage grafts generated from passaged OA chondrocytes underwent endochondral ossification after implantation either subcutaneously or in bone. Cartilage grafts integrated with host bone at 15 out of 16 junctions. Grafts variably remodeled into woven bone, with the proportion of bony repair tissue in tibial defects ranging from 22% to 85% (average 48%). Bony repair tissue bridged the tibial defects in half of the animals. In contrast, unmodified OA cartilage and engineered grafts formed from primary chondrocytes did not undergo endochondral ossification in vivo. hOA chondrocytes can adopt an endochondral phenotype after passaging and TGF-β superfamily treatment. Engineered endochondral cartilage grafts can integrate with host bone, undergo ossification, and heal critical-size long-bone defects in a mouse model. However, additional methods to further enhance ossification of these grafts are required before the clinical translation of this approach.

Binding and segmentation via a neural mass model trained with Hebbian and anti-Hebbian mechanisms.

PubMed

Cona, Filippo; Zavaglia, Melissa; Ursino, Mauro

2012-04-01

Synchronization of neural activity in the gamma band, modulated by a slower theta rhythm, is assumed to play a significant role in binding and segmentation of multiple objects. In the present work, a recent neural mass model of a single cortical column is used to analyze the synaptic mechanisms which can warrant synchronization and desynchronization of cortical columns, during an autoassociation memory task. The model considers two distinct layers communicating via feedforward connections. The first layer receives the external input and works as an autoassociative network in the theta band, to recover a previously memorized object from incomplete information. The second realizes segmentation of different objects in the gamma band. To this end, units within both layers are connected with synapses trained on the basis of previous experience to store objects. The main model assumptions are: (i) recovery of incomplete objects is realized by excitatory synapses from pyramidal to pyramidal neurons in the same object; (ii) binding in the gamma range is realized by excitatory synapses from pyramidal neurons to fast inhibitory interneurons in the same object. These synapses (both at points i and ii) have a few ms dynamics and are trained with a Hebbian mechanism. (iii) Segmentation is realized with faster AMPA synapses, with rise times smaller than 1 ms, trained with an anti-Hebbian mechanism. Results show that the model, with the previous assumptions, can correctly reconstruct and segment three simultaneous objects, starting from incomplete knowledge. Segmentation of more objects is possible but requires an increased ratio between the theta and gamma periods.

A DNA vaccine for Crimean-Congo hemorrhagic fever protects against disease and death in two lethal mouse models

PubMed Central

Fitzpatrick, Collin J.; Suschak, John J.; Richards, Michelle J.; Badger, Catherine V.; Six, Carolyn M.; Martin, Jacqueline D.; Hannaman, Drew; Zivcec, Marko; Bergeron, Eric; Koehler, Jeffrey W.; Schmaljohn, Connie S.

2017-01-01

Crimean-Congo hemorrhagic fever virus (CCHFV) is a tick-borne virus capable of causing a severe hemorrhagic fever disease in humans. There are currently no licensed vaccines to prevent CCHFV-associated disease. We developed a DNA vaccine expressing the M-segment glycoprotein precursor gene of CCHFV and assessed its immunogenicity and protective efficacy in two lethal mouse models of disease: type I interferon receptor knockout (IFNAR-/-) mice; and a novel transiently immune suppressed (IS) mouse model. Vaccination of mice by muscle electroporation of the M-segment DNA vaccine elicited strong antigen-specific humoral immune responses with neutralizing titers after three vaccinations in both IFNAR-/- and IS mouse models. To compare the protective efficacy of the vaccine in the two models, groups of vaccinated mice (7–10 per group) were intraperitoneally (IP) challenged with a lethal dose of CCHFV strain IbAr 10200. Weight loss was markedly reduced in CCHFV DNA-vaccinated mice as compared to controls. Furthermore, whereas all vector-control vaccinated mice succumbed to disease by day 5, the DNA vaccine protected >60% of the animals from lethal disease. Mice from both models developed comparable levels of antibodies, but the IS mice had a more balanced Th1/Th2 response to vaccination. There were no statistical differences in the protective efficacies of the vaccine in the two models. Our results provide the first comparison of these two mouse models for assessing a vaccine against CCHFV and offer supportive data indicating that a DNA vaccine expressing the glycoprotein genes of CCHFV elicits protective immunity against CCHFV. PMID:28922426

A DNA vaccine for Crimean-Congo hemorrhagic fever protects against disease and death in two lethal mouse models.

PubMed

Garrison, Aura R; Shoemaker, Charles J; Golden, Joseph W; Fitzpatrick, Collin J; Suschak, John J; Richards, Michelle J; Badger, Catherine V; Six, Carolyn M; Martin, Jacqueline D; Hannaman, Drew; Zivcec, Marko; Bergeron, Eric; Koehler, Jeffrey W; Schmaljohn, Connie S

2017-09-01

Crimean-Congo hemorrhagic fever virus (CCHFV) is a tick-borne virus capable of causing a severe hemorrhagic fever disease in humans. There are currently no licensed vaccines to prevent CCHFV-associated disease. We developed a DNA vaccine expressing the M-segment glycoprotein precursor gene of CCHFV and assessed its immunogenicity and protective efficacy in two lethal mouse models of disease: type I interferon receptor knockout (IFNAR-/-) mice; and a novel transiently immune suppressed (IS) mouse model. Vaccination of mice by muscle electroporation of the M-segment DNA vaccine elicited strong antigen-specific humoral immune responses with neutralizing titers after three vaccinations in both IFNAR-/- and IS mouse models. To compare the protective efficacy of the vaccine in the two models, groups of vaccinated mice (7-10 per group) were intraperitoneally (IP) challenged with a lethal dose of CCHFV strain IbAr 10200. Weight loss was markedly reduced in CCHFV DNA-vaccinated mice as compared to controls. Furthermore, whereas all vector-control vaccinated mice succumbed to disease by day 5, the DNA vaccine protected >60% of the animals from lethal disease. Mice from both models developed comparable levels of antibodies, but the IS mice had a more balanced Th1/Th2 response to vaccination. There were no statistical differences in the protective efficacies of the vaccine in the two models. Our results provide the first comparison of these two mouse models for assessing a vaccine against CCHFV and offer supportive data indicating that a DNA vaccine expressing the glycoprotein genes of CCHFV elicits protective immunity against CCHFV.

Mouse Models for Drug Discovery. Can New Tools and Technology Improve Translational Power?

PubMed

Zuberi, Aamir; Lutz, Cathleen

2016-12-01

The use of mouse models in biomedical research and preclinical drug evaluation is on the rise. The advent of new molecular genome-altering technologies such as CRISPR/Cas9 allows for genetic mutations to be introduced into the germ line of a mouse faster and less expensively than previous methods. In addition, the rapid progress in the development and use of somatic transgenesis using viral vectors, as well as manipulations of gene expression with siRNAs and antisense oligonucleotides, allow for even greater exploration into genomics and systems biology. These technological advances come at a time when cost reductions in genome sequencing have led to the identification of pathogenic mutations in patient populations, providing unprecedented opportunities in the use of mice to model human disease. The ease of genetic engineering in mice also offers a potential paradigm shift in resource sharing and the speed by which models are made available in the public domain. Predictively, the knowledge alone that a model can be quickly remade will provide relief to resources encumbered by licensing and Material Transfer Agreements. For decades, mouse strains have provided an exquisite experimental tool to study the pathophysiology of the disease and assess therapeutic options in a genetically defined system. However, a major limitation of the mouse has been the limited genetic diversity associated with common laboratory mice. This has been overcome with the recent development of the Collaborative Cross and Diversity Outbred mice. These strains provide new tools capable of replicating genetic diversity to that approaching the diversity found in human populations. The Collaborative Cross and Diversity Outbred strains thus provide a means to observe and characterize toxicity or efficacy of new therapeutic drugs for a given population. The combination of traditional and contemporary mouse genome editing tools, along with the addition of genetic diversity in new modeling systems, are synergistic and serve to make the mouse a better model for biomedical research, enhancing the potential for preclinical drug discovery and personalized medicine. © The Author 2016. Published by Oxford University Press.

Mice Expressing RHAG and RHD Human Blood Group Genes

PubMed Central

Goossens, Dominique; da Silva, Nelly; Metral, Sylvain; Cortes, Ulrich; Callebaut, Isabelle; Picot, Julien; Mouro-Chanteloup, Isabelle; Cartron, Jean-Pierre

2013-01-01

Anti-RhD prophylaxis of haemolytic disease of the fetus and newborn (HDFN) is highly effective, but as the suppressive mechanism remains uncertain, a mouse model would be of interest. Here we have generated transgenic mice expressing human RhAG and RhD erythrocyte membrane proteins in the presence and, for human RhAG, in the absence, of mouse Rhag. Human RhAG associates with mouse Rh but not mouse Rhag on red blood cells. In Rhag knockout mice transgenic for human RHAG, the mouse Rh protein is “rescued” (re-expressed), and co-immunoprecipitates with human RhAG, indicating the presence of hetero-complexes which associate mouse and human proteins. RhD antigen was expressed from a human RHD gene on a BAC or from RHD cDNA under control of β-globin regulatory elements. RhD was never observed alone, strongly indicative that its expression absolutely depends on the presence of transgenic human RhAG. This first expression of RhD in mice is an important step in the creation of a mouse model of RhD allo-immunisation and HDFN, in conjunction with the Rh-Rhag knockout mice we have developed previously. PMID:24260394

Influence of radiation quality on mouse chromosome 2 deletions in radiation-induced acute myeloid leukaemia.

PubMed

Brown, Natalie; Finnon, Rosemary; Manning, Grainne; Bouffler, Simon; Badie, Christophe

2015-11-01

Leukaemia is the prevailing neoplastic disorder of the hematopoietic system. Epidemiological analyses of the survivors of the Japanese atomic bombings show that exposure to ionising radiation (IR) can cause leukaemia. Although a clear association between radiation exposure and leukaemia development is acknowledged, the underlying mechanisms remain incompletely understood. A hemizygous deletion on mouse chromosome 2 (del2) is a common feature in several mouse strains susceptible to radiation-induced acute myeloid leukaemia (rAML). The deletion is an early event detectable 24h after exposure in bone marrow cells. Ultimately, 15-25% of exposed animals develop AML with 80-90% of cases carrying del2. Molecular mapping of leukaemic cell genomes identified a minimal deleted region (MDR) on chromosome 2 (chr2) in which a tumour suppressor gene, Sfpi1 is located, encoding the transcription factor PU.1, essential in haematopoiesis. The remaining copy of Sfpi1 has a point mutation in the coding sequence for the DNA-binding domain of the protein in 70% of rAML, which alters a single CpG sequence in the codon for arginine residue R235. In order to identify chr2 deletions and Sfpi.1/PU.1 loss, we performed array comparative genomic hybridization (aCGH) on a unique panel of 79rAMLs. Using a custom made CGH array specifically designed for mouse chr2, we analysed at unprecedentedly high resolution (1.4M array- 148bp resolution) the size of the MDR in low LET and high-LET induced rAMLs (32 X-ray- and 47 neutron-induced). Sequencing of Sfpi1/PU.1DNA binding domain identified the presence of R235 point mutations, showing no influence of radiation quality on R235 type or frequency. We identified for the first time rAML cases with complex del2 in a subset of neutron-induced AMLs. This study allowed us to re-define the MDR to a much smaller 5.5Mb region (still including Sfpi1/PU.1), identical regardless of radiation quality. Crown Copyright © 2015. Published by Elsevier B.V. All rights reserved.

LBH589, A Hydroxamic Acid-Derived HDAC Inhibitor, is Neuroprotective in Mouse Models of Huntington’s Disease

PubMed Central

Chopra, Vanita; Quinti, Luisa; Khanna, Prarthana; Paganetti, Paolo; Kuhn, Rainer; Young, Anne B.; Kazantsev, Aleksey G.; Hersch, Steven

2016-01-01

Background: Modulation of gene transcription by HDAC inhibitors has been shown repeatedly to be neuroprotective in cellular, invertebrate, and rodent models of Huntington’s disease (HD). It has been difficult to translate these treatments to the clinic, however, because existing compounds have limited potency or brain bioavailability. Objective: In the present study, we assessed the therapeutic potential of LBH589, an orally bioavailable hydroxamic acid-derived nonselective HDAC inhibitor in mouse models of HD. Method: The efficacy of LBH589 is tested in two HD mouse models using various biochemical, behavioral and neuropathological outcome measures. Results: We show that LBH589 crosses the blood brain barrier; induces histone hyperacetylation and prevents striatal neuronal shrinkage in R6/2 HD mice. In full-length knock-in HD mice LBH589-treatment improves motor performance and reduces neuronal atrophy. Conclusions: Our efficacious results of LBH589 in fragment and full-length mouse models of HD suggest that LBH589 is a promising candidate for clinical assessment in HD patients and provides confirmation that non-selective HDAC inhibitors can be viable clinical candidates. PMID:27983565